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PHSC1100 Dr. Tavossi's Class. Fall 2014.

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Physical Science Final Exam

Question 1 of 128

1

The International System of Units, SI Units, or metrics units of: length, mass, and time are:

Select one of the following:

  • m, kg, min

  • m, kg, h

  • ft, slug, s

  • m, kg, s

  • cm, g, s

Explanation

Question 2 of 128

1

The power in SI-Unit is measured in Watt, that is related to energy by being equal to

Select one of the following:

  • energy times time

  • energy consumed

  • energy wasted

  • energy times distance

  • energy per unit time

Explanation

Question 3 of 128

1

The energy source most used in the United States is

Select one of the following:

  • coal

  • water

  • natural gas

  • oil

  • biomass (wood)

Explanation

Question 4 of 128

1

The two factors that influence energy consumption are:

Select one of the following:

  • supply and demand

  • resource and price

  • cost and production

  • lifestyle and efficiency

Explanation

Question 5 of 128

1

If you started with a $1,600 investment and you had $12,800 after 6 years, what would be the annual interest rate you received?

Select one of the following:

  • 14%

  • 15%

  • 35%

  • 19%

Explanation

Question 6 of 128

1

What is the amount of power in kilowatts consumed per capita in the United States?

Select one of the following:

  • 2 kW

  • 3 kW

  • 12 kW

  • 5 kW

Explanation

Question 7 of 128

1

Running a clothes dryer for 90 minutes (1.5 hours) at 1600 Watts will cost about ____ cents if the cost of electricity is 10 cents per kWh:

Select one of the following:

  • 4 cents

  • 10 cents

  • 50 cents

  • 24 cents

Explanation

Question 8 of 128

1

The growth rate of GDP of a certain country is 3.5% per year. This means that the GDP is doubling every ____

Select one of the following:

  • 2 years

  • 10 years

  • 5 years

  • 20 years

Explanation

Question 9 of 128

1

A simple machine, such as a set of pulleys and ropes, known as block and tackle, are devices or tools that multiply applied-force, and changes its direction, at the expense of:

Select one of the following:

  • speed

  • velocity

  • distance

  • acceleration

Explanation

Question 10 of 128

1

The following statement is describing which of the three Newton's Laws of Motion? When no-net force is acting is acting on an object, if it is at rest it remains at rest, or if it is in motion, it can only move at a constant velocity.

Select one of the following:

  • First law

  • Second law

  • Third law

  • Law of gravity

Explanation

Question 11 of 128

1

According to Newton's second law of motion, when a net-force acts on an object, the object must be ____

Select one of the following:

  • accelerating

  • going at a constant speed

  • moving at constant velocity

  • at rest

Explanation

Question 12 of 128

1

According to Newtons third law, if the push that the car tires give to the road-surface is the action force, the the reaction force is

Select one of the following:

  • the weight of the car

  • the force of the car upon the tires

  • the friction force of the road-surface on the tires

  • the acceleration of the car

Explanation

Question 13 of 128

1

If a 60 kg person is observed to accelerate at the rate of 4 m/s(^2), the net force responsible for this is

Select one of the following:

  • 240 N

  • 100 N

  • 120 N

  • 140 N

Explanation

Question 14 of 128

1

A car having an initial speed of 9 m/s starts to accelerate at the rate of 4 m/s(^2), the final speed after 5.5 seconds is

Select one of the following:

  • 25 m/s

  • 15 m/s

  • 19 m/s

  • 31 m/s

Explanation

Question 15 of 128

1

A car is moving at 22 m/s (50 mph), when driver sees the traffic light turning red and immediately applies the brakes, decelerating at 6 m/s(^2). What is the car's stopping distance, neglecting the driver's reaction times?

Select one of the following:

  • 30.4 m

  • 10.2 m

  • 20.3 m

  • 40.3 m

Explanation

Question 16 of 128

1

If a stone is dropped from a bridge that is 133 m above the water, how long will it take until the stone hits the water?

Select one of the following:

  • 1.7 s

  • 5.2 s

  • 3.1 s

  • 6.2 s

Explanation

Question 17 of 128

1

A ball is projected straight downward with an initial speed of 20 m/s. After 3 seconds, about how fast is it going?

Select one of the following:

  • 30 m/s

  • 45.4 m/s

  • 49.4 m/s

  • 60.5 m/s

Explanation

Question 18 of 128

1

A ball is projected straight up at an initial speed of 24.5 m/s. After 2.5 seconds, what is it's speed?

Select one of the following:

  • 9.8 m/s

  • 14.7 m/s

  • 4.9 m/s

  • 0 m/s

Explanation

Question 19 of 128

1

How much work is required to increase the velocity of a 4 kg car from rest to 5 m/s?

Select one of the following:

  • 100 J

  • 200 J

  • 20 J

  • 50 J

Explanation

Question 20 of 128

1

The gravitational potential energy of an object, near the Earth's surface, and the work done to lift the object to the height "h" is given by

Select one of the following:

  • weight times height

  • mass times height

  • mass times speed

  • mass times acceleration

Explanation

Question 21 of 128

1

From work-KE theorem, what is the speed of a car of mass 2500 kg, after it is pushed by a force of 500 N over a horizontal distance of 10 m?

Select one of the following:

  • 1 m/s

  • 4 m/s

  • 2 m/s

  • 3 m/s

Explanation

Question 22 of 128

1

When a car is braked to a stop, it's kinetic energy is transformed into

Select one of the following:

  • stopping energy

  • energy of motion

  • potential energy

  • heat energy

Explanation

Question 23 of 128

1

Our nose cracker moved back and forth as shown. The kinetic energy will be greatest at what point?
(A -> B -> C)

Select one of the following:

  • A

  • B

  • A and C

  • halfway between A and B

Explanation

Question 24 of 128

1

The efficiency of a lightbulb is the ratio of the

Select one of the following:

  • energy input to the energy out of the bulb

  • light output of the bulb to the electrical energy input

  • heat energy out to the electrical energy in

  • voltage output of the bulb to the power input

Explanation

Question 25 of 128

1

If the energy conversion efficiencies in a 3 step process are 36% for the first step, 44% for the second, and 26% for the third, the overall efficiency is about:

Select one of the following:

  • 4%

  • 9%

  • 0.4%

  • 2%

Explanation

Question 26 of 128

1

For a fossil fueled electrical generating plant, 10,000 Btus of chemical energy input into the plant will result in about how many Btus of waste heat dumped into the environment if the efficiency of power plant is 35%?

Select one of the following:

  • 8,800 Btus

  • 10,000 Btus

  • 4,080 Btus

  • 6,500 Btus

Explanation

Question 27 of 128

1

The first law of thermodynamics states that: heat added to the system, plus work done on the system, equals change in the total energy of the system. This statement is based on-

Select one of the following:

  • how heat can be conducted

  • how temperature is increased

  • the principle of conservation of energy

  • the state of the system

Explanation

Question 28 of 128

1

The second law of thermodynamics states that heat energy flows in the direction of

Select one of the following:

  • up, since heat rises

  • higher temperature

  • lower temperature

  • lower entropy

Explanation

Question 29 of 128

1

The total R-value of a wall made of different layers of materials is obtained by

Select one of the following:

  • multiplying the R values of each layer

  • the sum of R values for each layer

  • sum of areas of each layer

  • sum of thicknesses of each layer

Explanation

Question 30 of 128

1

When ice crystals form in the clouds,

Select one of the following:

  • phase change from solid to liquid occurs

  • the thermal mass of the atmosphere increases

  • heat energy is released

  • the atmosphere becomes colder

Explanation

Question 31 of 128

1

The R-value of material is not related to its

Select one of the following:

  • composition

  • area

  • thickness

  • resistance to heat flow

Explanation

Question 32 of 128

1

An object with a very high specific heat will

Select one of the following:

  • decrease in temperature very fast if removed from the source

  • lose its heat very fast

  • always be water

  • take considerably more heat to raise its temperature

Explanation

Question 33 of 128

1

The efficiency of an electric motor is the ratio of the

Select one of the following:

  • energy into the motor to the energy out of it

  • heat released to rotational energy

  • heat plus electricity produced to the electrical input

  • shaft work output to the electrical energy input

Explanation

Question 34 of 128

1

For a furnace to provide 80,000 Btu/h of thermal energy to a living space, what should the rate of heat supplied by the fuel be if the furnace efficiency is 65%?

Select one of the following:

  • 103,000 Btu

  • 15,300 Btu

  • 123,000 Btu

  • 223,000 Btu

Explanation

Question 35 of 128

1

A heat engine ____

Select one of the following:

  • converts work into heat energy

  • can be 100% efficient in the absence of friction

  • can have no cold sink

  • needs a hot source and a cold sink to be able to work

Explanation

Question 36 of 128

1

The heat transfer by conduction through an area 10ft x 7ft section of the wall, with R-value of 35 (ft^2-F-h/Btu), with temperature difference between the sides change in temperature equaling 10 degrees farenheit, will be

Select one of the following:

  • 10 Btu/h

  • 35 Btu/h

  • 15 Btu/h

  • 20 Btu/h

Explanation

Question 37 of 128

1

Since the rate of heat transfer by conduction is proportion to the change in temperature, what percent savings in your cooling bill would you expect if you turned the thermostat up from 70 degrees to 74 degrees, and the outside temperature is 95 degrees?

Select one of the following:

  • 26%

  • 46%

  • 6%

  • 16%

Explanation

Question 38 of 128

1

Thermal radiations are electromagnetic waves and like all EM waves are of the type

Select one of the following:

  • transverse waves

  • longitudinal waves

  • surface waves

  • torsional waves

Explanation

Question 39 of 128

1

Normally the phase changes from vapor to liquid to solid takes place in that order when the heat is

Select one of the following:

  • kept constant

  • pressure is reduced

  • added

  • removed

Explanation

Question 40 of 128

1

85 degrees Fahrenheit is equal to ____ temperature in Kelvin scale

Select one of the following:

  • 286 K

  • 308 K

  • 316 K

  • 302 K

Explanation

Question 41 of 128

1

The Carnot efficiency (maximum possible efficiency) of a heat engine operating between 20 degrees C and 2000 degrees C will be about ____. (Note: the temperature must be in Kelvins -> C + 273)

Select one of the following:

  • 35%

  • 100%

  • 72%

  • 87%

Explanation

Question 42 of 128

1

A heat pump will have an efficiency of about ____

Select one of the following:

  • 35%

  • 100%

  • 200%

  • 50%

Explanation

Question 43 of 128

1

What are the percentages of Infra-Red (IR), Ultra Violet (UV), and Visible Light in the solar radiation at the top of the Earth's atmosphere?

Select one of the following:

  • 17% IR, 37% UV, 46% visible

  • 37% IR, 5% UV, 58% visible

  • 51% IR, 12% UV, 37% visible

  • 47% IR, 7% UV, 46% visible

Explanation

Question 44 of 128

1

The amount of infrared radiation emitted, or absorbed, by an object, apart from the temperature difference with the surroundings, and the surface area, depends also on

Select one of the following:

  • shape

  • color, surface texture

  • its type of material

  • density

Explanation

Question 45 of 128

1

What is the wavelength of the electromagnetic waves emitted by a Satellite-TV, that has typically a frequency of 12 GHz? (GHz= 10^9 Hz)

Select one of the following:

  • 0.015 m

  • 0.025 m

  • 0.035 m

  • 0.013 m

Explanation

Question 46 of 128

1

Specific heat of a substance is defined as the

Select one of the following:

  • heat required to increase its temper by one-degree Fahrenheit

  • heat required to increase its temperature by one-degree Celsius

  • heat required to increase its heat by one joule

  • heat required to increase the temperature one one unite mass by one degree

Explanation

Question 47 of 128

1

How much heat energy is required to increase the temperature of 3 kg of water from room temperature of 20 degrees C to the boiling point 100 degrees C? (Specific heat of water in SI units is C= 4186 J/kg*C)

Select one of the following:

  • 20.4 kJ

  • 50.6 kJ

  • 100.5 kJ

  • 789.7 kJ

Explanation

Question 48 of 128

1

What produces the cooling in a refrigerator?

Select one of the following:

  • evaporation of Freon outside

  • compression on Freon inside

  • condensation of Freon

  • evaporation of Freon inside

Explanation

Question 49 of 128

1

The geothermal heat, that is, the heat from the interior of the earth, can be used to warm or cool a house

Select one of the following:

  • in a certain area

  • near hot water springs

  • eight feet below the ground everywhere

  • more than 100 feet underground

Explanation

Question 50 of 128

1

A wall of a typical house is made of six layers with R-values given in (ft^2- F - h/Btu); from interior dead air later (R1= 0.68), 0.5 in sheetrock (R2= 0.45), 5.5 in fiberglass insulation (R3= 19), 0.5 in plywood (R4= 0.63), exterior dead air layer (R5 = 0.68). If temperature difference between outside and inside is 22 degrees F, and the total area of the wall is 360 ft^2 the rate of heat transfer by conduction is ____.

Select one of the following:

  • 567.4 Btu/h

  • 156.3 Btu/h

  • 369.4 Btu/h

  • 423.6 Btu/h

Explanation

Question 51 of 128

1

The Carnot efficiency of a heat engine operating between 21 degrees C and 1200 degrees C will be about

Select one of the following:

  • 52%

  • 78%

  • 80%

  • 90%

Explanation

Question 52 of 128

1

Amount of heat and temperature of an object are different because amount of heat depends on the

Select one of the following:

  • temperature difference

  • energy of its molecules

  • size of its molecules

  • amount of substance

Explanation

Question 53 of 128

1

The first law of thermodynamics is related to the

Select one of the following:

  • conservation of energy

  • heat and temperature

  • entropy and temperature

  • heat and work

Explanation

Question 54 of 128

1

To keep an iced drink cold for the longest time, what color cup would you use?

Select one of the following:

  • red

  • blue

  • white

  • black

Explanation

Question 55 of 128

1

Suppose it takes 48,000 Btu to heat up the water in a tank. If the heating element has an output of 2,800 W, then how long will it take to heat up the water, assuming no extra heat losses?

Select one of the following:

  • 2 h

  • 5 h

  • 30 mins

  • 3 h

Explanation

Question 56 of 128

1

The existence of the four seasons, in the mid-latitude locations, is due to the

Select one of the following:

  • moon-earth interaction

  • variation of the sun-earth distance

  • tilt of rotation axis of the earth by 23.5 degrees

  • variation of the moon-earth distance

Explanation

Question 57 of 128

1

Heat transfers by all three ways; conduction, convection, and radiation; are directly proportional to the....

Select one of the following:

  • surface temperature

  • surface roughness

  • surface color

  • surface area

Explanation

Question 58 of 128

1

The optimal angle of tilt, from the horizontal, for a south facing flat-plate solar collector, or photovoltaic cells panel, in a location with the latitude of 50.5 degrees N, for the purpose of solar panels installation is

Select one of the following:

  • 50.5 degrees

  • 60.5 degrees

  • 20.5 degrees

  • 30.5 degrees

Explanation

Question 59 of 128

1

What is the main advantage of using thermal mass, in the form of thick concrete floor, or Trombe wall, in a direct-gain passive solar system?

Select one of the following:

  • to increase temperature fluctuations during the night

  • to provide foundation support for the collector superstructure

  • to increase the insolation on south-facing windows

  • to reduce temperature fluctuations during the day

Explanation

Question 60 of 128

1

During what season will more insolation be delivered to a vertical south-facing window on a clear day?

Select one of the following:

  • fall

  • winter

  • spring

  • summer

Explanation

Question 61 of 128

1

The insolation in a certain location is 900 W/m^2 and 85% of this is direct component on the collector. If a useful rate of energy needed for cooking is 150 W, then what area of the solar collector oven in the form of parabolic mirror is needed to intercept this amount of radiation, take the efficiency to 20%?

Select one of the following:

  • 0.98 m^2

  • 1.2 m^2

  • 1.6 m^2

  • 0.87 m^2

Explanation

Question 62 of 128

1

Determine the collector area needed to heat 554 lbs of water (80 gallons), in one day, from 50 degrees F to 130 degrees F, if the insolation is 1700 Btu/d/ft^2 and the FPC efficiency is 48%.

Select one of the following:

  • 54 ft^2

  • 62 ft^2

  • 73 ft^2

  • 33 ft^2

Explanation

Question 63 of 128

1

The main difference between transverse and longitudinal waves is that transverse waves

Select one of the following:

  • travel faster than longitudinal waves

  • are not shear waves

  • can not be polarized

  • can be polarized

Explanation

Question 64 of 128

1

A typical microwave generates the electromagnetic waves of frequency 2.45 GHz (1 Giga= 10^9). The wavelength of the radio wave corresponding to the frequency is

Select one of the following:

  • 9.26 cm

  • 8.48 cm

  • 11.45 cm

  • 12.24 cm

Explanation

Question 65 of 128

1

In prospection for ore by gravimetric method, (to measure the variation of g=9.8 m/s^2 on the earths surface at a fixed height) how do you distinguish between petroleum and ore?

Select one of the following:

  • g would be greater over an ore deposit than a petroleum deposit

  • density of ore is less than petroleum

  • g does not change over the surface of the earth

  • g would be greater over a petroleum deposit than an ore deposit

Explanation

Question 66 of 128

1

When seismic waves (or light waves) travel from one medium into another medium with different wave-speed, what is the difference between reflection and refraction, at the interface between the two media?

Select one of the following:

  • Refracted wave bends and goes through the second medium

  • reflection and refraction are the same effect

  • reflection can only occur on a smooth interface

  • refraction will not bend the direction of the waves

Explanation

Question 67 of 128

1

What is the main difference between electromagnetic waves and sound waves?

Select one of the following:

  • electromagnetic waves can travel in a vacuum

  • sound waves travel faster

  • sound waves can be polarized

  • sound waves can travel in a vacuum

Explanation

Question 68 of 128

1

The magnitude of gravitational attraction between a 135 kg-person and a 290,000 kg-door of a bunker, with 0.2 m distance between their centers of mass is ____. (G= 6.674 x 10^-11 n*m2/kg2)

Select one of the following:

  • 6.53 x 10^-2 N

  • 7.64 x 10^-3

  • 8.75 x 10^-3

  • 5.42 x 10^-2

Explanation

Question 69 of 128

1

In a fractionating tower of an oil-refinery, where crude oil is heated from the bottom to separate different hydrocarbon constituents, what is the least volatile constituent of crude oil? That is, the component with the highest boiling point?

Select one of the following:

  • industrial fuel oil

  • kerosene

  • gasoline

  • asphalt

Explanation

Question 70 of 128

1

The longevity of a fossil-fuel reserve is determined by the ratio of

Select one of the following:

  • proven reserves/ daily production production rate

  • proven reserves / yearly production rate

  • indicated reserves / yearly production rate

  • inferred reserves yearly production rate

Explanation

Question 71 of 128

1

Pressure on a surface inside a fluid is due to the

Select one of the following:

  • force of gravity

  • rotational energy of fluid molecules

  • surface tension

  • continuous knocking of fluid molecules on the surface

Explanation

Question 72 of 128

1

Static pressure at a depth h below the surface of a fluid is given by

Select one of the following:

  • mass x g x h

  • density x g x h

  • force x time x h

  • h x g x volume

Explanation

Question 73 of 128

1

A swimming pool has a depth of 2.5 m. What is the gauge pressure at the bottom of this pool, in psi? (Density of water is pw= 1000 kg/m3)

Select one of the following:

  • 3.553 psi

  • 4.652 psi

  • 7.324 psi

  • 1.334 psi

Explanation

Question 74 of 128

1

The normal blood pressure is expressed as 80 to 120 mm-of-mercury, which are gauge pressure values. When these values are converted into psi they become ____

Select one of the following:

  • 1.432, 2.133 psi

  • 1.547, 2.320 psi

  • 1.652, 2.358 psi

  • 1.321, 2.142 psi

Explanation

Question 75 of 128

1

A balloon in the air is buoyed up by a force equal to the

Select one of the following:

  • weight of the air it displaces

  • weight of the balloon and its contents

  • mass of air displace

  • density of the surrounding air

Explanation

Question 76 of 128

1

What is the buoyant force on a 3 ton ship that is floating in the sea?

Select one of the following:

  • 2.5 tons

  • 3.0 tons

  • 3.5 tons

  • 1.5 tons

Explanation

Question 77 of 128

1

Why do you expect photochemical smog to be a greater problem in a city like Los Angeles than in a heavily industrialized city like Pittsburgh?

Select one of the following:

  • LA has more automobile traffic

  • LA gets more days with temperature inversion

  • LA is less windy

  • Pittsburg has more desulfurization plants

Explanation

Question 78 of 128

1

The acidity of rain, or other solutions, is measured by the pH number scale that varies from 0 to 14. What does a pH number represent?

Select one of the following:

  • 10 to the positive power of the hydrogen ion concentration

  • the larger the pH number the stronger the acidity

  • the smaller the pH number the less acidic the solution is

  • 10 to the negative power of the hydrogen ion concentration in the solution

Explanation

Question 79 of 128

1

The pressure exerted on your finger if you hold up a 15 lb box of apples, if the contact surface of your finger is 0.25 in x 0.25 in, would be ____

Select one of the following:

  • 200 psi

  • 220 psi

  • 240 psi

  • 160 psi

Explanation

Question 80 of 128

1

Suppose it takes 38,500 Btu to heat up water in a tank. If the heating element has an output power of 2,500 W, then how long would it take to heat up the water, assuming no extra heat losses? (1 Btu= 1055 Joules, 1 Watt = 1 Joule per second, 1 hour = 3600 s)

Select one of the following:

  • 55 mins

  • 2.5 hours

  • 3.5 hours

  • 4.5 hours

Explanation

Question 81 of 128

1

During which season will more insolation be delivered to a vertical south facing window on a clear day?

Select one of the following:

  • Winter

  • Fall

  • Spring

  • Summer

Explanation

Question 82 of 128

1

The optimum angle of tilt from the horizontal, for a flat plate solar collector, or panels of photovoltaic cells, both facing South, in a location with a latitude of 50.5 degrees North, for the purpose of solar panel installations is

Select one of the following:

  • 30.5 degrees

  • 40.5 degrees

  • 50.5 degrees

  • 60.5 degrees

Explanation

Question 83 of 128

1

The measure of the angle of position of the sun from the South direction is called the

Select one of the following:

  • altitude

  • azimuth

  • declination

  • inclination

Explanation

Question 84 of 128

1

If the insolation (I) upon a flat plate collector is 890 (Btu/ft2*day), how large must the area A of the collector be to provide (Q/t= 12,400 Btu/hr of thermal energy for one day (24 hours)? Take the collector efficiency to be 57.5% (Note: Btu/h is related to I A and E by Q/t = I*A*E)

Select one of the following:

  • 18 ft2

  • 164 ft2

  • 376 ft2

  • 637 ft2

Explanation

Question 85 of 128

1

The acidity of rain, or a solution, is measured by the pH number, that varies from 0 to 14, what does a pH number represent?

Select one of the following:

  • 10 to the positive power represent the hydrogen ion concentration per mole

  • the larger the pH the stronger the acidity of the solution

  • 10 to the negative power of the hydrogen ion concentration per mole in the solution

  • the smaller the pH the less acidic the solution

Explanation

Question 86 of 128

1

Pressure on a surface is defined as

Select one of the following:

  • mass x speed

  • mass x velocity

  • density x volume

  • force per unit area

Explanation

Question 87 of 128

1

Pressure on a surface inside a fluid is caused by

Select one of the following:

  • weight of fluid molecules

  • force of gravity

  • potential energy of fluid molecules

  • repeated knocking of the fluid molecules on the surface

Explanation

Question 88 of 128

1

Static pressure at a depth h in a fluid is given by

Select one of the following:

  • h x g x volume

  • mass x g x h

  • force x time x h

  • density x g x h

Explanation

Question 89 of 128

1

Atmospheric pressure, at sea level, is 14.7 psi, the gauge pressure of an automobile tire is 38 psi, the absolute pressure of this tire in Pascal is..... (Note: 1 psi = 6895 Pa)

Select one of the following:

  • 131,100 Pa

  • 248,200 Pa

  • 353,300 Pa

  • 363,400 Pa

Explanation

Question 90 of 128

1

A balloon in the air is buoyed up by a force equal to the ___

Select one of the following:

  • density of the surrounding air

  • atmospheric pressure

  • weight of the balloon and its contents

  • weight of the air it displaces

Explanation

Question 91 of 128

1

Which of the following air pollutants is emitted in about equal amounts by stationary and mobile sources?

Select one of the following:

  • particulates

  • carbon monoxide

  • nitrogen oxides

  • sulfur dioxides

Explanation

Question 92 of 128

1

Ozone layer in the stratosphere

Select one of the following:

  • dissipates within days

  • combines with NO or NO2 to produce smog

  • absorbs infrared light from the sun

  • provides protection from incoming UV solar radiation

Explanation

Question 93 of 128

1

How much has the global temperature on earth changed over the past 100 years?

Select one of the following:

  • 0.5 degrees C

  • 1.0 degrees C

  • 1.5 degrees C

  • 2.0 degrees C

Explanation

Question 94 of 128

1

One of the fundamentals of electrostatic is that the force between two unlike charges is

Select one of the following:

  • repulsive

  • neutralized

  • attractive

  • zero

Explanation

Question 95 of 128

1

Electricity is transmitted from plower plants at ____ to reduce by Joule heating in the transmission lines, which is about 10%.

Select one of the following:

  • high currents

  • low resistance

  • high resistance

  • high voltage

Explanation

Question 96 of 128

1

What quantity is the same for three resistors in a series circuit?

Select one of the following:

  • power

  • resistance

  • current

  • voltage

Explanation

Question 97 of 128

1

What quantity is the same for three resistors in a parallel circuit?

Select one of the following:

  • power

  • resistance

  • current

  • voltage

Explanation

Question 98 of 128

1

A circuit consists of one lightbulb of resistance of 144 ohms and another lightbulb of 240 ohms that are wired in series to a 120 V wall socket outlet. What is the current through this circuit?

Select one of the following:

  • 0.10 A

  • 0.20 A

  • 0.30 A

  • 0.40 A

Explanation

Question 99 of 128

1

Two resistors of 144 ohms and 240 ohms are wired in parallel to 120 V wall outlet socket outlet, the current through the 240 ohm resistor will be

Select one of the following:

  • 0.3 A

  • 0.4 A

  • 0.5 A

  • 0.6 A

Explanation

Question 100 of 128

1

The electrostatic force of attraction between two charges of q1= -35 x 10^-6 C and q2 = +69 x 10^-6 C, separated by a distance of 3 m is ___

Select one of the following:

  • 0.4 N

  • 1.21 N

  • 2.41 N

  • 3.53 N

Explanation

Question 101 of 128

1

A high temperature superconductor compounds such as YBCO ____

Select one of the following:

  • provides large magnetic fields at room temperature

  • has no resistance at room temperature

  • has no electrical resistance below its critical temperature

  • generates constant voltage at low temperatures

Explanation

Question 102 of 128

1

A lightbulb draws a current of 2.5 amps, when connected to a wall outlet of 120 V. What is the resistance of the bulb?

Select one of the following:

  • 50 ohms

  • 100 ohms

  • 200 ohms

  • 300 ohms

Explanation

Question 103 of 128

1

The resistance of four light bulbs are given below. Which one has the highest wattage?

Select one of the following:

  • 144 ohms

  • 192 ohms

  • 240 ohms

  • 320 ohms

Explanation

Question 104 of 128

1

How much current is drawn by 3240 W electrical appliance operating at 240 V?

Select one of the following:

  • 11.3 A

  • 12.4 A

  • 13.5 A

  • 14.5 A

Explanation

Question 105 of 128

1

What is the cost of running your water heater of power rating 2800 W for 2.5 hours per day, for one year or 365 days, if the electricity costs 12 cents per kWh?

Select one of the following:

  • $95

  • $105

  • $206

  • $307

Explanation

Question 106 of 128

1

The magnetic field of a bar magnet is similar to that produced by

Select one of the following:

  • a horse shoe magnet

  • a straight current carrying wire

  • two coils separated by long distance

  • a current carrying solenoid

Explanation

Question 107 of 128

1

Alternating current has an advantage over direct current because

Select one of the following:

  • batteries can be displaced in most circuits

  • electrical generators can be made

  • produces no heat loss

  • one can step up, or down, the amount of voltage used

Explanation

Question 108 of 128

1

A transformer (adaptor) can only operate if

Select one of the following:

  • the power in equals the power out

  • an alternating current is used

  • the potential difference is large enough

  • we step down the current

Explanation

Question 109 of 128

1

If the current through a 33 ohm resister and a 57 ohm resistor in series is 5 A, then the total voltage drop across both of these resistors will be

Select one of the following:

  • 110 V

  • 120 V

  • 340 V

  • 450 V

Explanation

Question 110 of 128

1

What transformer turns-ratio of secondary to primary is required to lower the voltage from 120 V wall socket outlet to 8 V for charging a cell phone?

Select one of the following:

  • 15

  • 0.044

  • 0.075

  • 0.067

Explanation

Question 111 of 128

1

A bird sitting on a bare high voltage wire is not electrocuted because ____

Select one of the following:

  • of the high resistance of its body

  • its body is at a low electrical potential compared to the wire

  • the high voltage across its feet produced a small current

  • there is no electrical potential difference across its body because the other wire is out of reach

Explanation

Question 112 of 128

1

For a photovoltaic cell of 0.5 V and of area 1 cm2, the maximum output power is 135 mW (mW= 10^-3 W). What is the current provided by this cell?

Select one of the following:

  • 0.01 A

  • 0.02 A

  • 0.23 A

  • 0.27 A

Explanation

Question 113 of 128

1

The site location for a wind turbine is especially important. If the power output goes as the cube of the wind velocity, then which of the following average velocities will give approximately 8 times as much output as 10 mph winds?

Select one of the following:

  • 5 mph

  • 10 mph

  • 15 mph

  • 20 mph

Explanation

Question 114 of 128

1

If the average wind speed for 24 hours is 16 mph at one site but 13 mph at another site for 12 hours and then 23 mph for 12 hours at another site, how much output can be expected from the first turbine compared to the turbine at the second site?

Select one of the following:

  • 35%

  • 46%

  • 57%

  • 68%

Explanation

Question 115 of 128

1

A 1000 MW power plant is shut down for one day (24 hours). What is the loss of income from this plant if the selling price were 10 cents/kWh (1 MW=10^6 kW).

Select one of the following:

  • $180,000

  • $700,000

  • $2,400,000

  • $3,500,000

Explanation

Question 116 of 128

1

For the following circuit, with all the bulbs identical, what is true for the brightness of the lights?
l -----------l (A)
l l_____
l (B) l l (C)
l _______ l ____ l

Select one of the following:

  • A = B = C

  • A = 4B = 4C

  • A = .5B = .5C

  • A = B, C = 0

Explanation

Question 117 of 128

1

The existence of atom was proposed by Democritus (420 BCE) and at the beginning of the 19th century, John Dolton proved that every element has an atom, by the ____

Select one of the following:

  • law of electrostatics

  • ideal gas law

  • law of definite proportion

  • law of conservation of energy

Explanation

Question 118 of 128

1

The discovery of atomic nucleus was made by firing fast moving ____ at a thin gold foil

Select one of the following:

  • alpha particles

  • gamma rays

  • electrons

  • neutrons

Explanation

Question 119 of 128

1

The isotopes of an element all have the same number of

Select one of the following:

  • protons

  • electrons

  • positron neutrons

  • nucleons

Explanation

Question 120 of 128

1

For the same energy, the most penetrating type of radiations are

Select one of the following:

  • B-particles

  • X-rays

  • a-particles

  • y-rays

Explanation

Question 121 of 128

1

The half-life of a radioactive nuclide is the time taken for _____

Select one of the following:

  • half of its neutrons to decay

  • half of its electrons to decay

  • half of its mass to decay

  • half of its nuclei to decay

Explanation

Question 122 of 128

1

At 9 am on Monday, a radioactive sample contained 80 million nuclei. At 9 am on Saturday, 2.5 million of these nuclei are left over and has not decayed. The half life of the sample is

Select one of the following:

  • 1.5 days

  • 1 day

  • 5 days

  • 4 days

Explanation

Question 123 of 128

1

The radioactive isotope Cobalt-60 decays into Nickel-60 by beta emission, with a half life of 5.3 years. If we start with 100 gram of Co-60, after how many years will we have only 390 milligrams of it left?

Select one of the following:

  • 20

  • 42

  • 89

  • 6

Explanation

Question 124 of 128

1

The activity of Carbon-14 in the living organism today is 15.3 disintegrations per minute, per gram. Half-life of Carbon-14 is 5730 years. If the activity of an archaeological sample, due to the carbon-14 is 3.825 disintegrations per min, per gram, how old is the sample?

Select one of the following:

  • 2865

  • 5730

  • 11460

  • 22920

Explanation

Question 125 of 128

1

The binding energy of a Helium nucleus is 4.5 x 10^-12 Joules (28.4 MeV). What is the total binding energy of 4-grams (one mol.) of Helium that has avogadro's number NA= 6.02 x 10^23 of nuclei, when this mass is converted into radiant energy in the interior of the Sun?

Select one of the following:

  • 1.7 x 10^11 J

  • 2.7 x 10^12 J

  • 1.2 x 10^10 J

  • 3.4 x 10^13 J

Explanation

Question 126 of 128

1

The pair production and annihilation refer to the simultaneous production of a particle and its anti-particle by two energetic gamma-ray photons, near a nucleus, and the destruction of a particle and an anti-particle, as a result of collision between them, these particles and anti-particles can be _____

Select one of the following:

  • electron and positron

  • proton and electron

  • proton and neutron

  • two neutrons

Explanation

Question 127 of 128

1

In the following fission reaction, the atomic number Z and mass number of nucleus A of the unknown element Y are:
(0/1)n + (92/235)U --> (53/135)I + (Z/A)Y + (0/2)n

Select one of the following:

  • 38, 102

  • 39, 99

  • 39, 100

  • 37, 100

Explanation

Question 128 of 128

1

If a light-weight stable nucleus has 12 neutrons, the atomic mass is expected to be _____. (1 atomic mass unit = 1.66 x 10^-27 kg).

Select one of the following:

  • 18 amu

  • 24 amu

  • 36 amu

  • 6 amu

Explanation

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