Pregunta 1
Pregunta
The two water molecules shown above are electric dipoles. Which direction does the electric field produced by the left molecule point at the position of the right molecule?
Pregunta 2
Pregunta
Referring to the same figure, in its configuration shown, the water molecule at right will experience its?
Respuesta
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Minimum possible torque and potential energy.
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Minimum possible torque and maximum possible potential energy.
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Maximum possible torque and minimum possible potential energy
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Maximum possible torque and potential energy
Pregunta 3
Pregunta
Electric dipole field strengths are proportional to the inverse cube of the distance from the source. How would the field experience by the water molecule at right change if its distance to the left water molecule decrease by a factor of two?
Respuesta
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E would decrease by a factor of 8
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E would decrease by a factor of 4
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E would increase by a factor of 4
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E would increase by a factor of 8
Pregunta 4
Pregunta
“The whole is the sum of the parts” is a pretty good plain language expression of
Respuesta
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The principle of superposition
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Gauss’s law.
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Potential energy per charge.
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is minus the gradient of
Pregunta 5
Pregunta
Suppose you needed to determine the electric field produced by a uniformly charged cube of charge. Which method below would not work?
Respuesta
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Breaking the cube up into small parts, finding the piece of the field from each part, and adding them all up component-by-component.
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Applying Gauss’s law as a field calculator.
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Breaking the cube up into small parts, finding the voltage from the parts, adding them all up, and then calculating how the voltage changes with position.
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This
Pregunta 6
Pregunta
Suppose you needed to determine the electric field from a set of six uniformly charged concentric spherically symmetric spherical shells. Which method below would be easiest to execute
Respuesta
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Breaking the shells up into small parts, finding the piece of the field from each part, and adding them all up component-by-component
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Applying Gauss’s law as a field calculator.
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Breaking the shells up into small parts, finding the voltage from the parts, adding them all up, and then calculating how the voltage changes with position
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This
Pregunta 7
Pregunta
The diagram above shows a very long solid conducting cylinder carrying a uniform charge/length +q/L surrounded by a concentric conducting cylindrical shell that carries a charge/length −q/L. The cylinder divides space up into the four regions A, B, C, and D shown in the figure. The only region in space where E is not 0 is?
Pregunta 8
Pregunta
The geometry of the last problem screams “cylinder of radius r and length l” as the choice for Gaussian surface. The flux of the electric field E through this surface would be
Respuesta
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4pi*r^2 E
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2pi*r^2 E
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2pi*r*l E
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(4/3)pi*r^3 E
Pregunta 9
Pregunta
Which action below would not increase the capacitance of a parallel plate capacitor
Respuesta
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Fill the inter-plate gap with insulating oil
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Decrease the plate spacing
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Increase the plate area.
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Raise the voltage on the capacitor
Pregunta 10
Pregunta
A 1 uF parallel plate capacitor is connected to a 12 V battery. While remaining connected, the space between the two capacitor plates is filled with a dielectric with k =2 . After the space is completely filled, the voltage V and charge q on the capacitor are?
Respuesta
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V=12, q=24
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V=6, q=24
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V=6, q=12
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V=12, q=12
Pregunta 11
Pregunta
A different 1 uF parallel plate capacitor is connected to a 12 V battery and then disconnected. While disconnected, the space between the two capacitor plates is filled with a dielectric with k =2. After the space is completely filled, the voltage V and charge q on the capacitor are
Respuesta
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V=12, q=24
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V=6, q=24
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V=6, q=12
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V=12, q=12
Pregunta 12
Pregunta
The figure above shows a sketch of equipotentials. The number next to each curve shows the voltage. All points in the cross hatched area at the center are at the same voltage. A length scale is shown at lower right. The triangle, X, and two circles mark certain positions. Where is the E field largest?
Pregunta 13
Pregunta
Referring to the same figure, where does the field point vertically down?
Pregunta 14
Pregunta
The region inside the cross-hatched area is?
Respuesta
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Positively charged with electric field lines directed outwards.
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Negatively charged with electric field lines directed inwards
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Uncharged with zero electric field
Pregunta 15
Pregunta
Suppose a proton moving at a speed of 10 m/s at the position of the left circle is guided by the electric field to the position of the right circle. When it reaches the right circle, it will be moving