Faraday's law

Q1. According to Faraday’s law, the magnitude of the induced e.m.f. in a circuit depends on:

Multiple Choice · 1 point

• · The rate of change of magnetic flux linkage
• · The magnetic field strength only
• · The resistance of the circuit
• · The direction of the magnetic field

Q2. Magnetic flux through a single loop of wire changes from 0.020 Wb to 0.005 Wb in 0.50 s. What is the magnitude of the average induced e.m.f.?

Multiple Choice · 1 point

• · 0.015 V
• · 0.030 V
• · 0.010 V
• · 0.050 V

Q3. A coil has 200 turns. The magnetic flux through each turn changes at a rate of 0.004 Wb s⁻¹. What is the induced e.m.f.?

Multiple Choice · 1 point

• · 0.004 V
• · 0.200 V
• · 0.800 V
• · 50 V

Q4. If the magnetic flux density through a coil doubles while all other factors remain constant, what happens to the induced e.m.f.?

Multiple Choice · 1 point

• · It halves
• · It doubles
• · It remains the same
• · It becomes zero

Q5. Which change would NOT induce an e.m.f. in a coil?

Multiple Choice · 1 point

• · Increasing the magnetic field strength
• · Rotating the coil in the magnetic field
• · Increasing the number of turns of the coil while flux stays constant
• · Moving the coil into a magnetic field

Q6. A coil rotates faster in a magnetic field. What happens to the induced e.m.f.?

Multiple Choice · 1 point

• · It increases
• · It decreases
• · It stays constant
• · It becomes zero

Q7. The magnetic flux through a coil is constant but non-zero. What is the induced e.m.f.?

Multiple Choice · 1 point

• · Maximum
• · Alternating
• · Zero
• · Increasing

Q8. A coil with 100 turns experiences a change in magnetic flux from 0.01 Wb to 0.03 Wb in 0.10 s. What is the average induced e.m.f.?

Multiple Choice · 1 point

• · 0.20 V
• · 20 V
• · 2.0 V
• · 0.02 V

Q9. If the number of turns in a coil is doubled while the rate of change of flux remains the same, what happens to the induced e.m.f.?

Multiple Choice · 1 point

• · It halves
• · It doubles
• · It remains the same
• · It becomes zero

Q10. Which of the following would increase the magnitude of the induced e.m.f. in a generator coil?

Multiple Choice · 1 point

• · Reducing the magnetic field strength
• · Rotating the coil more slowly
• · Increasing the rate of change of magnetic flux
• · Keeping the magnetic flux constant

Q11. A generator coil has 150 turns and an area of 0.020 m². It rotates in a magnetic field of flux density 0.40 T at an angular speed of 100 rad s⁻¹. What is the maximum induced e.m.f.?

Multiple Choice · 1 point

• · 60 V
• · 120 V
• · 12 V
• · 300 V

Q12. A generator coil with 200 turns and area 0.015 m² rotates in a uniform magnetic field of 0.50 T with angular speed 80 rad s⁻¹. What is the instantaneous e.m.f. when ωt = 30°?

Multiple Choice · 1 point

• · 60 V
• · 120 V
• · 30 V
• · 240 V