Class 12 Physics MCQ – AC Generator

This set of Class 12 Physics Chapter 7 Multiple Choice Questions & Answers (MCQs) focuses on “AC Generator”.

1. A 100 turn coil of area 0.1 m² rotates at half a revolution per second. It is placed in a uniform magnetic field of 0.01 T perpendicular to the axis of rotation of the coil. Calculate the maximum voltage generated in the coil?
a) 256.33 V
b) 89.12V
c) 0.314 V
d) 3.1455 V
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2. An a.c. generator consists of a coil of 1000 turns and cross-sectional area of 3m², rotating at a constant angular speed of 60 rad s^-1 in a uniform magnetic field 0.04 T. The resistance of the coil is 500Ω. Calculate the maximum current drawn from the generator.
a) 2500 A
b) 14.4 A
c) 6.25 A
d) 0.55 A
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3. Adithya peddles a stationary bicycle the pedals of which are attached to a 500 turn coil of area 11 m². The coil rotates at half a revolution per second and it is placed in a uniform magnetic field of 20.5 T perpendicular to the axis of rotation of the coil. What is the maximum voltage generated in the coil?
a) 354035 V
b) 85000V
c) 111647 V
d) 46464 V
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4. Identify the principle behind the working of an a.c. generator.
a) Eddy currents
b) Faraday’s law
c) Lenz’s law
d) Electromagnetic induction
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5. An armature coil consists of 30 turns of wire, each of area A = 0.05 m² and total resistance of 10 Ω. It rotates in a magnetic field of 0.15T at a constant frequency of \(\frac {140}{\pi }\) Hz. Determine the value of maximum induced emf produced in the coil.
a) 1 V
b) 500 V
c) 63 V
d) 43 V
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6. In an a.c. generator, electrical energy is converted to mechanical energy by electromagnetic induction.
a) True
b) False
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7. ‘X’ is a rectangular coil consisting of a large number of turns of copper wire wound over a soft iron core in an a.c. generator. Identify X.
a) Slip ring
b) Armature
c) Copper brushes
d) Field magnet
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8. An a.c. generator consists of a coil of 50 turns and an area 2.5 m² rotating at an angular speed of 60 rad s^-1 in a uniform magnetic field of 0.3 T between two fixed pole pieces. What is the flux through the coil, when the current is zero?
a) Maximum
b) Minimum
c) Zero
d) Independent of current
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Sanfoundry Global Education & Learning Series – Physics – Class 12.

To practice all chapters and topics of class 12 Physics, here is complete set of 1000+ Multiple Choice Questions and Answers.

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