Alternating Current MCQs

Option A: Its electric field

Option B: Its coils

Option C: Its magnetic field

Option D: Both electric and magnetic fields

Correct Answer: Its magnetic field ✔

Option A: Each increase

Option B: Each decrease

Option C: Each remains the same

Option D: One increases whereas that in the other decreases

Correct Answer: Each decrease ✔

Option A: V√/√2R

Option B: V/√2√R

Option C: V02/√2R

Option D: 2/√2√R

Correct Answer: V02/√2R ✔

Option A: V = VR+VL+VC

Option B: V2 = VR2+VL2+VC2

Option C: V2 = VR2+(VL-VC)2

Option D: V2 = VL2+(VR-VC)2

Correct Answer: V2 = VR2+(VL-VC)2 ✔

Option A: Zero

Option B: 45°

Option C: 90°

Option D: 180°

Correct Answer: Zero ✔

Option A: Peak values of voltage and current

Option B: Effective values of voltage and current

Option C: Instantaneous values of voltage and current

Option D: All of the above

Correct Answer: All of the above ✔

Option A: 10mH

Option B: 12mH

Option C: 16mH

Option D: 20mH

Correct Answer: 16mH ✔

Option A: 1Ω

Option B: 5Ω

Option C: 7Ω

Option D: 7Ω

Correct Answer: 5Ω ✔

Option A: Zero

Option B: 2

Option C: 1

Option D: Not definite

Correct Answer: 1 ✔

Option A: DC circuit

Option B: AC circuits

Option C: Both AC and DC circuit

Option D: Full wave rectifier circuit

Correct Answer: AC circuits ✔

Option A: 220V

Option B: 220/ 2V

Option C: 110V

Option D: 220 √2V

Correct Answer: 220 √2V ✔

Option A: C/R

Option B: R/C

Option C: 1/RC

Option D: 1/ 2RC

Correct Answer: 1/RC ✔

Option A: 0.5 mH

Option B: 0.5H

Option C: 2.0H

Option D: 8.0H

Correct Answer: 0.5H ✔

Option A: Same

Option B: Different

Option C: At L will be more than at C

Option D: At L will be less than at C

Correct Answer: Same ✔

Option A: The exact value of the current

Option B: RMS value of the current

Option C: The net value of the current

Option D: The peak value of the current

Correct Answer: RMS value of the current ✔

Option A: (R+2πfL)

Option B: R+1/2πfL

Option C: (R2+f2L2)

Option D: (R2+4π2f2L2)

Correct Answer: (R2+4π2f2L2) ✔

Option A: Remains same

Option B: Brightness increases

Option C: Brightness decreases

Option D: No light

Correct Answer: Brightness increases ✔

Option A: 32Ω

Option B: 62Ω

Option C: 50Ω

Option D: 100Ω

Correct Answer: 32Ω ✔

Option A: Lags behind voltage by π/2

Option B: Is in phase with voltage

Option C: Opposite in phase of voltage by π

Option D: Leads forward the voltage by π/2

Correct Answer: Leads forward the voltage by π/2 ✔

Option A: The current lead voltage by phase angle is 90 degrees

Option B: The voltage leads current by phase angle is 90 degrees

Option C: The current lead voltage by phase angle is 45 degrees

Option D: The voltage leads current by phase angle is 45 degrees

Correct Answer: The current lead voltage by phase angle is 90 degrees ✔

Option A: Lagging each other

Option B: They are at 90? phase difference

Option C: They have zero phase difference

Option D: No phase difference

Correct Answer: They have zero phase difference ✔

Option A: I = 2I∫Sin(πt/2)

Option B: I = 2I∫Sin(2πt)

Option C: I = 2ISinπt

Option D: I = I∫sin(2πt)

Correct Answer: I = 2I∫Sin(2πt) ✔

Option A: Mean value of I2

Option B: Square root of mean value of I2

Option C: Square root of I2

Option D: Square of 1/2

Correct Answer: Square root of mean value of I2 ✔

Option A: 0.9sec

Option B: 15 sec

Option C: 1.5x105sec

Option D: 0.9x102sec

Correct Answer: 0.9sec ✔

Option A: Stationary

Option B: Longitudinal

Option C: Transverse

Option D: All the above

Correct Answer: Transverse ✔

Option A: Energy

Option B: Momentum

Option C: Mass

Option D: Heat

Correct Answer: Energy ✔

Option A: Perpendicular to electric field

Option B: Perpendicular to both electric and magnetic field

Option C: Perpendicular to magnetic field

Option D: Parallel to electric and magnetic field

Correct Answer: Perpendicular to both electric and magnetic field ✔

Option A: Magnetic field

Option B: Electric field

Option C: Electromagnetic force

Option D: Artificial gravitational field

Correct Answer: Electromagnetic force ✔

Option A: 20A

Option B: 20.66A

Option C: 6.66A

Option D: 5.66A

Correct Answer: 5.66A ✔

Option A: Average current

Option B: Sinusoidal current

Option C: r.m.s current

Option D: Net current

Correct Answer: r.m.s current ✔

Option A: Twice

Option B: One half

Option C: Four times

Option D: None

Correct Answer: One half ✔

Option A: Sound waves

Option B: Electromagnetic waves

Option C: Radio waves

Option D: Modulated waves

Correct Answer: Electromagnetic waves ✔

Option A: Electric and magnetic fields moving parallel to each other

Option B: Magnetic field moving with velocity of light in space

Option C: Electric field moving with velocity of light

Option D: Electric and magnetic fields moving perpendicular to each other

Correct Answer: Electric and magnetic fields moving perpendicular to each other ✔

Option A: λ-rays

Option B: Positive rays

Option C: Cathode rays

Option D: More than sound waves

Correct Answer: λ-rays ✔

Option A: fluctuates off and on

Option B: varies in magnitude alone

Option C: changes its direction again and again

Option D: changes its magnitude harmonically and reverses its direction of flow after regularly recurring intervals

Correct Answer: changes its direction again and again ✔