MCQOPTIONS
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MCQOPTIONS
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 | |
| 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 | |
| 3. |
In an a.c. generator, electrical energy is converted to mechanical energy by electromagnetic induction. |
| A. | True |
| B. | False |
| Answer» C. | |
| 4. |
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 |
| Answer» D. 43 V | |
| 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. | |
| 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 | |
| 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 500Ω. 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 | |
| 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 | |