Explore topic-wise MCQs in Physics.

This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Physics knowledge and support exam preparation. Choose a topic below to get started.

1.

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
Answer» B. Minimum
Discussion
2.

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
Answer» C. Copper brushes
Discussion
3.

In an a.c. generator, electrical energy is converted to mechanical energy by electromagnetic induction.

A. True
B. False
Answer» C.
Discussion
4.

An armature coil consists of 30 turns of wire, each of area A = 0.05 m2 and total resistance of 10 . 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
Answer» D. 43 V
Discussion
5.

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
Answer» E.
Discussion
6.

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
Answer» B. 85000V
Discussion
7.

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 500 . Calculate the maximum current drawn from the generator.

A. 2500 A
B. 1.44 A
C. 6.25 A
D. 0.55 A
Answer» C. 6.25 A
Discussion
8.

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
Answer» D. 3.1455 V
Discussion