NEET UG Physics Practice Paper – Electromagnetic Induction (Set 10)

Attempt all 30 MCQs and check your score instantly.

1. Faraday’s law states EMF is proportional to:

dΦ/dt
Φ
I
R

2. Unit of magnetic flux:

Weber
Tesla
Volt
Ampere

3. Lenz law gives:

direction
magnitude
resistance
current

4. Induced EMF formula:

-dΦ/dt
IR
V
none

5. Magnetic flux is:

BA cosθ
B/A
A/B
none

6. Self inductance unit:

Henry
Tesla
Volt
Ohm

7. Inductor opposes:

change in current
voltage
resistance
none

8. Energy stored in inductor:

½LI²
LI
I²
none

9. Eddy currents are:

induced currents
direct current
AC
none

10. Fleming right hand rule gives:

direction of induced current
force
voltage
none

11. Mutual inductance depends on:

geometry
current
voltage
none

12. Transformer works on:

mutual induction
self induction
Ohm law
none

13. EMF induced due to motion is:

motional EMF
static EMF
none
zero

14. Motional EMF formula:

Blv
IR
V
none

15. Induced current direction by Lenz law:

opposes cause
supports cause
random
none

16. Inductance depends on:

geometry
current
voltage
none

17. Time constant (LR):

L/R
R/L
LR
none

18. Induced EMF sign negative due to:

Lenz law
Ohm law
Newton law
none

19. Transformer voltage ratio:

Vp/Vs = Np/Ns
Vs/Vp
none
zero

20. Efficiency of transformer:

high
low
zero
none

21. Back EMF is:

opposing EMF
aiding EMF
zero
none

22. Inductor behaves as:

resistance to change
capacitor
conductor
none

23. Magnetic energy stored depends on:

current
voltage
resistance
none

24. Eddy currents cause:

heat loss
gain
zero
none

25. Laminated core reduces:

eddy currents
voltage
current
none

26. Generator works on:

EMI
Ohm law
motion
none

27. Induced current exists when:

flux changes
constant flux
zero flux
none

28. Magnetic flux unit:

Weber
Tesla
Volt
none

29. Self induction occurs in:

same coil
different coil
none
zero

30. Mutual induction occurs in:

two coils
one coil
none
zero

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NEET UG Physics Notes – Electromagnetic Induction (Set 10)

Electromagnetic Induction (EMI) is a high-scoring and concept-based chapter in NEET UG Physics. It focuses on how changing magnetic fields produce electric currents. This chapter is very important because it forms the basis of generators, transformers, and many real-life electrical devices.

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1. Magnetic Flux (Φ)

Magnetic flux represents the total magnetic field passing through a surface.$$\Phi = B A \cos\theta$$Φ=BAcosθ

Key Points:

• $B$B = magnetic field
• $A$A = area
• $\theta$θ = angle between field and normal
• Unit: Weber (Wb)

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2. Faraday’s Laws of Electromagnetic Induction

First Law:

Whenever magnetic flux linked with a circuit changes, an EMF is induced.

Second Law:

$$\text{EMF} = -\frac{d\Phi}{dt}$$EMF=−dtdΦ​

Important Insight:

• Faster change in flux → greater induced EMF

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3. Lenz’s Law

Lenz’s law gives the direction of induced current.

Statement:

The induced current always opposes the cause producing it.

Meaning:

• If flux increases → current produces opposite field
• If flux decreases → current tries to maintain it

The negative sign in Faraday’s law represents this.

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4. Motional EMF

When a conductor moves in a magnetic field, EMF is induced.$$\text{EMF} = B l v$$EMF=Blv

Where:

• $l$l = length of conductor
• $v$v = velocity

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5. Self Induction

Self induction occurs when change in current in a coil induces EMF in the same coil.$$\text{EMF} = -L \frac{dI}{dt}$$EMF=−LdtdI​

Self Inductance (L):

• Measures ability of coil to oppose change in current
• Unit: Henry (H)

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6. Mutual Induction

Occurs when change in current in one coil induces EMF in another coil.$$\text{EMF} = -M \frac{dI}{dt}$$EMF=−MdtdI​

Key Points:

• Depends on distance and orientation of coils
• Used in transformers

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7. Energy Stored in Inductor

$$U = \frac{1}{2} L I^2$$U=21​LI2

Insight:

• Energy stored in magnetic field of coil

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8. Eddy Currents

Eddy currents are loops of induced currents in conductors.

Effects:

• Cause heat loss
• Reduce efficiency

Applications:

• Induction heating
• Magnetic braking

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9. Reduction of Eddy Currents

Method:

• Use laminated core

Reason:

• Increases resistance → reduces current loops

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10. Transformer

A transformer transfers electrical energy using mutual induction.

Voltage Ratio:

$$\frac{V_p}{V_s} = \frac{N_p}{N_s}$$Vs​Vp​​=Ns​Np​​

Types:

• Step-up transformer
• Step-down transformer

Efficiency:

• Very high (≈ 95–99%)

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11. Back EMF

Back EMF is induced EMF that opposes applied EMF.

Occurs in:

• Motors
• Inductors

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12. Time Constant (LR Circuit)

$$\tau = \frac{L}{R}$$τ=RL​

Meaning:

• Time taken for current to reach ~63% of final value

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13. Generator

A generator converts mechanical energy into electrical energy.

Principle:

• Based on electromagnetic induction

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14. Conditions for Induced Current

Induced current exists only when:

✔ Magnetic field changes
✔ Area changes
✔ Angle changes

👉 If flux is constant → No induced current

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15. Important NEET Concepts

Must Remember:

• $\Phi = BA\cos\theta$Φ=BAcosθ
• $E = -\frac{d\Phi}{dt}$E=−dtdΦ​
• $E = Blv$E=Blv
• $U = \frac{1}{2}LI^2$U=21​LI2
• $\tau = L/R$τ=L/R

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16. Common Mistakes

❌ Ignoring negative sign (Lenz law)
❌ Confusing flux with magnetic field
❌ Forgetting conditions for induction
❌ Mixing self and mutual induction

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17. Quick Revision Tips

• EMF depends on rate of change of flux
• Lenz law always opposes change
• Transformer questions are very common
• Motional EMF is frequently asked

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Conclusion

Electromagnetic Induction is a concept + formula-based chapter and very scoring in NEET.

If you focus on:

• Faraday’s laws
• Lenz law
• Induction formulas
• Transformers

👉 You can easily score full marks from this chapter.