Free Alternating Current MCQs with Answers
592 Alternating Current MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alternating current varies periodically, so phase relationships become essential when current passes through a resistor, capacitor or inductor. The chapter distinguishes resistance from capacitive and inductive reactance, explains phase lead and lag, and connects changing electric and magnetic fields with the production and properties of electromagnetic waves.
Last updated
Read the Alternating Current notesFree MDCAT chapter notes with key terms592 questions · page 19 of 30
- A. The potential of a conductor increases when the charge on it decreases, but this affects the charge stored in it.
- B. The potential of a conductor is greatly reduced when the charge on it increases.
- C. The potential of a conductor increases without affecting the charge stored in it.
- D. The potential of a conductor is greatly reduced without affecting the charge stored in it.
- E. The potential of a conductor increases as the charge on it increases.
Explanation: The correct answer is that the potential of a conductor is greatly reduced without affecting the charge in it.
Correct answer: The potential of a conductor is greatly reduced without affecting the charge stored in it.- A. Forward
- B. Reverse
- C. Mid
- D. Positive
Explanation: Correct option is A. A diode works in forward bias for rectification. Rectification is the process of converting alternating current (AC)…
Correct answer: Forward- A. 4.4 sin(314t) mA
- B. 4.4 sin(157t) mA
- C. 6.2 sin(314t) mA
- D. 6.2 sin(157t) mA
Explanation: The correct answer is 6.2 sin(314t) mA. The root mean square voltage (VRMS) of 220V is used to find the peak voltage (Vmax), which is…
Correct answer: 6.2 sin(314t) mA- A. 2 A
- B. √2 A
- C. 1 A
- D. (1/√2)A
Explanation: The RMS (Root Mean Square) value of a sinusoidal alternating current is given by dividing the peak current by √2.
Correct answer: 1 A- A. Transformers
- B. Inductors
- C. Capacitors
- D. Motor
Explanation: Converting energy from one form to another is the key to understanding the differences between electric motors and generators.
Correct answer: Motor- A. Polarization
- B. Refraction
- C. Interference
- D. Diffraction
Explanation: Only transverse waves can undergo polarisation. Longitudinal waves cannot undergo polarization.
Correct answer: Polarization- A. Oscillating electric charges and their fields
- B. Neutral particles in motion
- C. Stationary electric charges
- D. Heat transfer
- E. None of the above
Explanation: Electromagnetic waves are the combination of electric and magnetic field waves produced by moving charges.The creation of all…
Correct answer: Oscillating electric charges and their fields- A. 120 km
- B. 100 km
- C. 80 km
- D. 140 km
Explanation: λ = v / fInputting speed of light or 3 x 108 m/s as v and 3 x 103 Hz as f gives us 1 x 105 m or 100 km.
Correct answer: 100 km- A. Green shift
- B. Red shift
- C. Blue shift
- D. None of these options is correct
Explanation: When a star emits light, the color of its light as observed on earth depends on its motion relative to earth.
Correct answer: Red shift- A. Beta rays
- B. Alpha rays
- C. Gamma rays
- D. All of these
Explanation: Out of all these, Gamma rays are an example of electromagnetic waves, which require NO medium to travel and propagate from one place to…
Correct answer: Gamma rays- A. Light
- B. Radiation
- C. Current
- D. None of these
Explanation: Substances that emit gamma radiation are used as tracers. To find a leak or blockage, the radioactive material is put into one end of the…
Correct answer: Radiation- A. Radio waves
- B. None of these
- C. X ray region
- D. Visible light
- E. All of these
Explanation: The visible light region falls between the ultraviolet (UV) and infrared (IR) regions on the electromagnetic spectrum.
Correct answer: Visible light- A. Electric field
- B. Magnetic field
- C. EM waves
- D. None of these
Explanation: Correct Option: CThis option is correct because accelerating charges produce changing electric fields and magnetic fields.
Correct answer: EM waves- A. X-rays
- B. Beta rays
- C. Gamma rays
- D. Electromagnetic rays
Explanation: Microwave ovens heat food using microwaves, a form of electromagnetic radiation similar to radio waves.
Correct answer: Electromagnetic rays- A. IR
- B. UV
- C. Alpha
- D. All of these
Explanation: Ozone is known for its ability to absorb and scatter ultraviolet radiation from the sun.
Correct answer: UV- A. Radio waves → gamma rays → ultraviolet → infra-red
- B. Radio waves → infra-red → ultraviolet → gamma rays
- C. Ultraviolet → gamma rays → radio waves → infra-red
- D. Ultraviolet → infra-red → radio waves → gamma rays
Explanation: Electromagnetic waves don't require a medium to travel. They are 7 types, each of them having the same kind of vibrations but different…
Correct answer: Radio waves → infra-red → ultraviolet → gamma rays- A. Radio waves
- B. X-rays
- C. Light waves
- D. Sound waves
Explanation: Factual. Electromagnetic waves include:Gamma rays, X rays, Ultra violet, Visible light, Infra-Red, Microwaves, RADIO WAVES.So, D is not a…
Correct answer: Sound waves- A. Ir>uv> visible > microwave > radio frequency
- B. Microwave >ir> visible >uv> radio frequency
- C. Radio frequency > microwave >ir> visible >uv
- D. Visible >ir>uv> microwave > radio wave
Explanation: Radio frequency > microwave >ir> visible >uvD. Visible >ir>uv> microwave > radio wave this is the correct arrangement of wavelength in the…
Correct answer: Radio frequency > microwave >ir> visible >uv- A. Light energy
- B. Sound energy
- C. Tidal energy
- D. Geothermal energy
Explanation: Light energy comes in the form of visible radiation. The energy emitted in the form of visible radiation is called light energy.
Correct answer: Light energy- A. Short
- B. Long
- C. Unchanged
- D. Variable
Explanation: In electromagnetic wave spectrum frequency and wavelength are inversely proportional.
Correct answer: Short