Copy and Edit

Generators of high frequency electromagnetic waves. Frequency ranges used in physiotherapy. Inductive and capacitive methods. Determination of the power of electromagnetic wave sources. Safety technique - Medical Physics -MCQs

Description

Medical Physics Quiz on Generators of high frequency electromagnetic waves. Frequency ranges used in physiotherapy. Inductive and capacitive methods. Determination of the power of electromagnetic wave sources. Safety technique - Medical Physics -MCQs, created by Hussain Basheer on 23/11/2018.
Hussain Basheer
Quiz by Hussain Basheer, updated more than 1 year ago
Hussain Basheer
Created by Hussain Basheer about 6 years ago
280
5
0

Resource summary

Question 1

Question
Which of the following human organs and tissues have the least thermal conductivity?
Answer
  • Muscles
  • Brain
  • Skin and fat

Question 2

Question
Which of the following diagnostic/therapeutic methods cause deep tissue heating?
Answer
  • Thermography
  • High frequency electric current therapy
  • Deep x-ray therapy

Question 3

Question
Faradization is a method for:
Answer
  • Electro-stimulation with low frequency pulsed current
  • High frequency electromagnetic therapy
  • Interferential current therapy of deep-seated tissue

Question 4

Question
The most common frequency used in high-frequency electro-stimulation is:
Answer
  • 20 Hz
  • 20 kHz
  • 2 MHz

Question 5

Question
Modern electromyography methods rely on the following parameter (chose one):
Answer
  • Rheobase
  • Chronaxie
  • Accommodation coefficient

Question 6

Question
Thermography is a medical imaging method that:
Answer
  • Is harmless
  • Has high resolution
  • With diagnostic significance similar to MRI

Question 7

Question
Which of the following body fluids and tissues has the least electrical conductivity?
Answer
  • Blood
  • Bones
  • Bone marrow

Question 8

Question
Electric resistance (R) is inversely proportional to:
Answer
  • Electric conductance (G)
  • Frequency (f)
  • Period (T)

Question 9

Question
What is the main effect that causes heating in microwave diathermy, and also in the microwave oven (f = 2.45 GHz)?
Answer
  • Resonance: water molecules oscillate with the same frequency
  • Dielectric heating: electric dipoles of water are made to rotate
  • Refraction: bending of waves inside the substance

Question 10

Question
Electric potential difference is measured in units of volts (V) that represent the ratio of:
Answer
  • Charge per time, Q/t
  • Energy per charge, E/Q
  • Energy per distance, E/x

Question 11

Question
Which of following electric currents is the most dangerous for the human body?
Answer
  • High frequency AC
  • Low frequency AC
  • Pulsed current

Question 12

Question
Which of the following currents will cause stimulation in excitable tissue (nerves or muscles)?
Answer
  • Low frequency, pulsed, above threshold
  • Low frequency, alternating, below threshold
  • High frequency, alternating, above threshold

Question 13

Question
High-frequency generators produce electromagnetic waves with:
Answer
  • Aperiodic behavior
  • Constant amplitude
  • Gradually damping amplitude

Question 14

Question
Which of the following currents causes differential heating in tissues?
Answer
  • Pulsed current
  • High frequency current
  • DC current

Question 15

Question
Which of the following features are common forelectrosurgery and electrostimulation?
Answer
  • The frequency
  • The shape of the electrodes
  • The use of alternating current

Question 16

Question
Specific heat capacity is defined as:
Answer
  • The amount of heat needed to raise the temperature of 1 kg of substance by 1 degree Kelvin (or Celsius)
  • The heat released during the controlled burn of 1 kg of substance
  • The heat gain in a substance when Gibbs free energy increases by 1 joule

Question 17

Question
Electrosurgical procedures apply alternating current in the radio frequency (RF) range (100 kHz - 5 MHz) directly to the tissue. Why during electrosurgery there is no nerve and muscular stimulations?
Answer
  • High frequencies currents do not penetrate deep enough
  • Oscillations are much faster than membrane depolarization time
  • The power is below stimulation threshold

Question 18

Question
What is the heating mechanism of high frequency alternating current (2MHz)?
Answer
  • Brief polarization of tissue
  • Oscillations of ionized molecules, rotation of dipoles and associated collisions
  • Absorption of energy from the electromagnetic waves

Question 19

Question
When an inductor (L) and a capacitor (C) are connected in series, the resulting (L-C) electric circuit is called:
Answer
  • Operational amplifier (compares and amplifies signal)
  • Current rectifier (converts AC into DC)
  • Harmonic oscillator (used to emit radio waves)

Question 20

Question
The Earth surface is (reasonably) constant potential reference, and for that reason taken to be the :
Answer
  • Infinite potential
  • Negative potential
  • Zero potential
Show full summary Hide full summary

Want to create your own Quizzes for free with GoConqr? Learn more.

Similar

Photosynthesis
ecarleton622
Concepts in Biology Final Exam
mlszala
PHYSICS P1 1
x_clairey_x
From Tsardom to communism- Russia
jk.99
Maths
Emmet McDonald
F211: Transport in animals keywords and info
Gurdev Manchanda
Mind Maps with GoConqr
Elysa Din
Plato's philosophy
Sumahlor
Biology Unit 1a - GCSE - AQA
RosettaStoneDecoded
Heartburn
mahmoud eladl
Admin 201 Exam
Aaron Torres
Browse Library