Electromagnetism – 100 Advanced & Numerical with Answers & Explanations | Board & MDCAT Preparation

100 Advanced & Numerical MCQs (Level -2) on Electromagnetism, Physics (Unit-Wise MCQs Practice):

---

👉Physics MCQs Hub – Unit wise Physics MCQs Practice (Main-Page)👈

---

Whether you are preparing for board examinations, chapter tests, college assessments, or competitive entrance exams (MDCAT, ECAT, NUST, PIEAS, GIKI, UET, FAST, and other engineering or medical admission tests), this comprehensive MCQ collection is designed to help you master Electromagnetism. The questions are arranged progressively—from basic concepts to advanced numerical problems and higher-order thinking—ensuring complete and systematic preparation for every type of examination.

This chapter-wise MCQ collection includes:

• 100 Basic MCQs Level-1 (1–100) – Covering magnetic fields, magnetic force, magnetic flux, Ampere's law, solenoids, galvanometers, transformers, alternating current, and other fundamental concepts.
• 100 Advanced & Numerical MCQs (101–200) – Focusing on formulas, calculations, magnetic fields, force on charges, transformer problems, AC circuits, inductance, and practical applications.
• 50 Higher-Order Thinking Skills (HOTS) MCQs (201–250) – Designed to strengthen analytical reasoning, conceptual understanding, and advanced problem-solving skills.
• 50 Challenging MCQs Quiz with Answers – A carefully selected mix of conceptual, numerical, and HOTS questions for quick revision and self-assessment.

This MCQ collection covers:

• Magnetic fields and magnetic force
• Magnetic flux and Ampere's Law
• Solenoids and current-carrying conductors
• Motion of charged particles in magnetic fields
• Velocity selector and cyclotron
• Torque on current loops and magnetic dipoles
• Galvanometer, ammeter, voltmeter, and multimeter
• Electromagnetic induction and Lenz's Law
• Self and mutual inductance
• Transformers and alternating current (AC)
• Reactance, impedance, resonance, and power factor
• Electromagnetic waves and Maxwell's theory
• Practical applications and measurement techniques

Every MCQ includes the correct answer with a clear, concept-based explanation to strengthen understanding, improve problem-solving skills, and reinforce key physics concepts.

This question bank helps students to:

• Build a strong conceptual foundation
• Improve numerical and analytical skills
• Master electromagnetism formulas and applications
• Avoid common examination mistakes
• Increase speed, accuracy, and confidence
• Prepare effectively for both board and competitive examinations

With 250 carefully selected MCQs arranged into 100 Basic, 100 Advanced & Numerical, and 50 HOTS MCQs, this all-in-one question bank provides complete preparation for Electromagnetism, making it an excellent resource for achieving success in both board examinations and competitive entrance tests.

---

Best Budget Laptops for Students for Study, Coding & Office Work 
(2026 Amazon Deals)

👉 Check Today’s Price on Amazon👈

👉 Check Acer Aspire 5 Price on Amazon

👉 Buy Lenovo IdeaPad Slim 3 on Amazon

👉 See HP Pavilion Latest Deal on Amazon

👉 View ASUS Vivobook 16 Details on Amazon

👉 Check MacBook Air Student Price on Amazon

---

Electromagnetism MCQs Level 2 – 100 Advanced & Numerical MCQs (MCQs 101–200)

---

MCQs No. 101

A proton enters a uniform magnetic field perpendicular to its direction of motion. The magnetic force acting on the proton is:

a. Along its velocity
b. Opposite to its velocity
c. Perpendicular to both velocity and magnetic field
d. Zero

Correct answer: c

Explanation: The magnetic force is given by F = qvB sinθ and always acts perpendicular to both the velocity of the charged particle and the magnetic field.

---

MCQs No. 102

A charge of 4 C moves with a speed of 5 m/s perpendicular to a magnetic field of 0.2 T. The magnetic force is:

a. 2 N
b. 4 N
c. 6 N
d. 8 N

Correct answer: b

Explanation:
F = qvB = 4 × 5 × 0.2 = 4 N.

---

MCQs No. 103

A conductor of length 0.40 m carries a current of 8 A perpendicular to a magnetic field of 0.50 T. The magnetic force is:

a. 0.8 N
b. 1.6 N
c. 2.4 N
d. 3.2 N

Correct answer: b

Explanation:

---

MCQs No. 104

A straight wire carries 8 A current. Find the magnetic field at a point 4 cm from the wire.

a. 2 × 10⁻⁵ T
b. 4 × 10⁻⁵ T
c. 8 × 10⁻⁵ T
d. 1.6 × 10⁻⁴ T

Correct answer: b

Explanation:

$$B=\frac{\mu_0 I}{2\pi r}$$
$$=\frac{4\pi\times10^{-7}\times8}{2\pi\times0.04} =4\times10^{-5}\text{ T}$$

---

MCQs No. 105

The radius of the circular path of a charged particle moving in a magnetic field becomes double when:

a. Magnetic field is doubled
b. Velocity is doubled
c. Charge is doubled
d. Mass is halved

Correct answer: b

Explanation: Since

$$r=\frac{mv}{qB}$$

the radius is directly proportional to velocity.

---

MCQs No. 106

A proton moves with speed 6 × 10⁶ m/s in a magnetic field of 0.03 T perpendicular to the field. Its path will be:

a. Straight line
b. Circular
c. Elliptical
d. Parabolic

Correct answer: b

Explanation: A charged particle moving perpendicular to a uniform magnetic field experiences centripetal force and moves in a circle.

---

MCQs No. 107

Magnetic flux through a surface is 0.6 Wb. If the area is doubled while the magnetic field remains constant, the flux becomes:

a. 0.3 Wb
b. 0.6 Wb
c. 1.2 Wb
d. 2.4 Wb

Correct answer: c

Explanation: Since Φ = BA, doubling the area doubles the magnetic flux.

---

MCQs No. 108

A magnetic flux changes from 4 Wb to 1 Wb in 0.5 s. The magnitude of induced emf is:

a. 2 V
b. 4 V
c. 6 V
d. 8 V

Correct answer: c

Explanation:

$$e=\frac{\Delta\Phi}{\Delta t} =\frac{4-1}{0.5}=6\text{ V}$$

---

MCQs No. 109

The induced emf in a coil depends directly upon:

a. Total magnetic flux
b. Rate of change of magnetic flux
c. Resistance of coil
d. Current in the coil

Correct answer: b

Explanation: Faraday's law states:

$$e=-N\frac{d\Phi}{dt}$$

---

MCQs No. 110

A coil has 200 turns. Flux through each turn changes by 0.01 Wb in 0.2 s. The induced emf is:

a. 5 V
b. 10 V
c. 20 V
d. 40 V

Correct answer: b

Explanation:

$$e=N\frac{\Delta\Phi}{\Delta t} =200\times\frac{0.01}{0.2} =10\text{ V}$$

---

MCQs No. 111

A coil has a self-inductance of 4 H. If current changes from 0 A to 2 A in 0.5 s, the induced emf is:

a. 8 V
b. 12 V
c. 16 V
d. 20 V

Correct answer: c

Explanation:

$$e=L\frac{\Delta I}{\Delta t} =4\times\frac{2}{0.5}=16\text{ V}$$

---

MCQs No. 112

The energy stored in a 5 H inductor carrying 4 A current is:

a. 20 J
b. 30 J
c. 40 J
d. 50 J

Correct answer: c

Explanation:

$$U=\frac12LI^2 =\frac12\times5\times16 =40\text{ J}$$

---

MCQs No. 113

An RL circuit has L = 3 H and R = 6 Ω. The time constant is:

a. 0.25 s
b. 0.5 s
c. 1 s
d. 2 s

Correct answer: b

Explanation:

$$\tau=\frac{L}{R}=\frac{3}{6}=0.5\text{ s}$$

---

MCQs No. 114

The SI unit of inductive reactance is:

a. Henry
b. Weber
c. Ohm
d. Tesla

Correct answer: c

Explanation: Inductive reactance opposes alternating current and is measured in ohms.

---

MCQs No. 115

A 1 H inductor is connected to a 100 Hz AC source. Its inductive reactance is approximately:

a. 157 Ω
b. 314 Ω
c. 628 Ω
d. 1256 Ω

Correct answer: c

Explanation:

$$X_L=2\pi fL =2\pi\times100\times1 \approx628\ \Omega$$

---

MCQs No. 116

A capacitor of 10 μF is connected to a 50 Hz supply. Its capacitive reactance is approximately:

a. 159 Ω
b. 318 Ω
c. 636 Ω
d. 1000 Ω

Correct answer: b

Explanation:

$$X_C=\frac1{2\pi fC} \approx318\ \Omega$$

---

MCQs No. 117

An AC source has a peak current of 14.14 A. Its RMS current is:

a. 5 A
b. 7.07 A
c. 10 A
d. 14.14 A

Correct answer: c

Explanation:

$$I_{rms}=\frac{I_0}{\sqrt2} =\frac{14.14}{1.414}=10\text{ A}$$

---

MCQs No. 118

An AC source has an RMS voltage of 220 V. The peak voltage is approximately:

a. 220 V
b. 250 V
c. 311 V
d. 440 V

Correct answer: c

Explanation:

$$V_0=\sqrt2V_{rms} =1.414\times220 \approx311\text{ V}$$

---

MCQs No. 119

A transformer has 400 turns in the primary and 100 turns in the secondary. If the primary voltage is 240 V, the secondary voltage is:

a. 30 V
b. 60 V
c. 120 V
d. 240 V

Correct answer: b

Explanation:

$$\frac{V_s}{V_p}=\frac{N_s}{N_p} =\frac{100}{400}$$
$$V_s=60\text{ V}$$

---

MCQs No. 120

A transformer has 200 turns in the primary and 800 turns in the secondary. It is a:

a. Current transformer
b. Step-down transformer
c. Step-up transformer
d. Isolation transformer

Correct answer: c

Explanation: Since the secondary has more turns than the primary, the output voltage increases.

---

MCQs No. 121

A magnetic field inside a solenoid is directly proportional to:

a. Radius only
b. Current only
c. Number of turns per unit length and current
d. Length only

Correct answer: c

Explanation: The magnetic field inside a long solenoid is

$$B=\mu_0nI$$

---

MCQs No. 122

The magnetic field inside a long solenoid having 1500 turns/m carrying 2 A current is approximately:

a. 1.26 × 10⁻³ T
b. 2.51 × 10⁻³ T
c. 3.77 × 10⁻³ T
d. 5.02 × 10⁻³ T

Correct answer: c

Explanation:

$$B=\mu_0nI$$
$$=4\pi\times10^{-7}\times1500\times2 \approx3.77\times10^{-3}\text{ T}$$

---

MCQs No. 123

A current-carrying conductor experiences maximum force when the angle between the conductor and magnetic field is:

a. 0°
b. 30°
c. 60°
d. 90°

Correct answer: d

Explanation: The magnetic force is maximum when sin θ = 1, i.e., θ = 90°.

---

MCQs No. 124

The average value of alternating current over one complete cycle is:

a. Maximum
b. RMS value
c. Zero
d. Peak value

Correct answer: c

Explanation: The positive and negative halves of an AC cycle cancel each other, giving an average value of zero.

---

MCQs No. 125

Which quantity remains unchanged when a charged particle moves only under the influence of a magnetic field?

a. Direction of velocity
b. Momentum direction
c. Speed (kinetic energy)
d. Radius of path

Correct answer: c

Explanation: A magnetic field changes only the direction of motion. Since the magnetic force is always perpendicular to the velocity, it does no work. Therefore, the particle's speed and kinetic energy remain constant.

---

MCQ No. 126

A current of 6 A flows through a long straight conductor. Calculate the magnetic field at a point 3 cm from the conductor.

a. $2 \times 10^{-5}$ T
b. $4 \times 10^{-5}$ T
c. $6 \times 10^{-5}$ T
d. $8 \times 10^{-5}$ T

Correct answer: b

Explanation:

Using,

$$B=\frac{\mu_0I}{2\pi r}$$
$$=\frac{4\pi\times10^{-7}\times6}{2\pi\times0.03} =4\times10^{-5}\text{ T}$$

---

MCQ No. 127

An electron enters a magnetic field of 0.02 T with a speed of 5 × 10⁶ m/s perpendicular to the field. The radius of its circular path is approximately:

a. 1.42 mm

b. 7.11 mm

c. 1.42 cm

d. 14.2 cm

Correct answer: a

Explanation:

$$r=\frac{mv}{qB}$$
$$=\frac{9.11\times10^{-31}\times5\times10^{6}} {1.6\times10^{-19}\times0.02} \approx1.42\times10^{-3}\text{ m}$$

= 1.42 mm

---

MCQ No. 128

The magnetic flux through a coil changes from 3 Wb to 0 Wb in 0.6 s. The induced emf is:

a. 2 V

b. 3 V

c. 5 V

d. 6 V

Correct answer: c

Explanation:

$$e=\frac{\Delta\Phi}{\Delta t} =\frac{3}{0.6} =5\text{ V}$$

---

MCQ No. 129

A coil has a self-inductance of 4 H. If the current changes uniformly from 1 A to 5 A in 0.5 s, the induced emf is:

a. 16 V

b. 24 V

c. 32 V

d. 40 V

Correct answer: c

Explanation:

$$e=L\frac{\Delta I}{\Delta t} =4\times\frac{4}{0.5} =32\text{ V}$$

---

MCQ No. 130

A transformer has 800 turns in the primary and 200 turns in the secondary. If the primary voltage is 240 V, the secondary voltage is:

a. 40 V

b. 50 V

c. 60 V

d. 80 V

Correct answer: c

Explanation:

$$\frac{V_s}{V_p}=\frac{N_s}{N_p}$$
$$V_s=240\times\frac{200}{800} =60\text{ V}$$

---

MCQ No. 131

An AC source has a peak voltage of 170 V. Its RMS voltage is:

a. 100 V

b. 120 V

c. 150 V

d. 170 V

Correct answer: b

Explanation:

$$V_{rms}=\frac{170}{\sqrt2} \approx120\text{ V}$$

---

MCQ No. 132

The inductive reactance of a 0.5 H inductor connected to a 50 Hz AC supply is:

a. 78.5 Ω

b. 157 Ω

c. 314 Ω

d. 628 Ω

Correct answer: b

Explanation:

$$X_L=2\pi fL =2\pi(50)(0.5) \approx157\Omega$$

---

MCQ No. 133

The capacitive reactance of a 50 μF capacitor connected to 50 Hz AC is approximately:

a. 31.8 Ω

b. 63.7 Ω

c. 95.5 Ω

d. 159 Ω

Correct answer: b

Explanation:

$$X_C=\frac1{2\pi fC}$$
$$=\frac1{2\pi(50)(50\times10^{-6})} \approx63.7\Omega$$

---

MCQ No. 134

An inductor of 3 H carries a current of 4 A. The energy stored in it is:

a. 12 J

b. 18 J

c. 24 J

d. 36 J

Correct answer: c

Explanation:

$$U=\frac12LI^2 =\frac12(3)(16) =24\text{ J}$$

---

MCQ No. 135

The angular frequency of an AC supply operating at 100 Hz is:

a. 100π rad/s

b. 150π rad/s

c. 200π rad/s

d. 400π rad/s

Correct answer: c

Explanation:

$$\omega=2\pi f =2\pi(100) =200\pi\text{ rad/s}$$

---

MCQ No. 136

A conductor 0.25 m long carries a current of 8 A in a magnetic field of 0.4 T. The magnetic force acting on it is:

a. 0.4 N

b. 0.8 N

c. 1.2 N

d. 1.6 N

Correct answer: b

Explanation:

$$F=BIL =0.4\times8\times0.25 =0.8\text{ N}$$

---

MCQ No. 137

A charge of 5 C moves perpendicular to a magnetic field of 0.4 T with a speed of 4 m/s. The magnetic force is:

a. 4 N

b. 6 N

c. 8 N

d. 10 N

Correct answer: c

Explanation:

$$F=qvB =5\times4\times0.4 =8\text{ N}$$

---

MCQ No. 138

The magnetic field inside a long solenoid having 1500 turns per metre and carrying a current of 3 A is approximately:

a. $2.8\times10^{-3}$ T

b. $4.5\times10^{-3}$ T

c. $5.7\times10^{-3}$ T

d. $7.5\times10^{-3}$ T

Correct answer: c

Explanation:

$$B=\mu_0nI$$
$$=4\pi\times10^{-7}\times1500\times3 \approx5.65\times10^{-3}\text{ T}$$

---

MCQ No. 139

An AC circuit has R = 8 Ω and X = 6 Ω. Its impedance is:

a. 8 Ω

b. 10 Ω

c. 12 Ω

d. 14 Ω

Correct answer: b

Explanation:

$$Z=\sqrt{R^2+X^2} =\sqrt{64+36} =\sqrt{100} =10\Omega$$

---

MCQ No. 140

The power consumed by an AC circuit with V = 240 V, I = 4 A and power factor = 0.75 is:

a. 540 W

b. 600 W

c. 720 W

d. 960 W

Correct answer: c

Explanation:

$$P=VI\cos\phi =240\times4\times0.75 =720\text{ W}$$

---

MCQ No. 141

The time constant of an RL circuit having L = 8 H and R = 4 Ω is:

a. 1 s

b. 2 s

c. 3 s

d. 4 s

Correct answer: b

Explanation:

$$\tau=\frac{L}{R} =\frac84 =2\text{ s}$$

---

MCQ No. 142

A coil experiences a change in magnetic flux of 0.8 Wb in 0.2 s. The induced emf is:

a. 2 V

b. 3 V

c. 4 V

d. 5 V

Correct answer: c

Explanation:

$$e=\frac{\Delta\Phi}{\Delta t} =\frac{0.8}{0.2} =4\text{ V}$$

---

MCQ No. 143

The RMS value of an alternating current having a peak value of 20 A is:

a. 10 A

b. 12.5 A

c. 14.1 A

d. 20 A

Correct answer: c

Explanation:

$$I_{rms}=\frac{20}{\sqrt2} \approx14.1\text{ A}$$

---

MCQ No. 144

The secondary voltage of an ideal transformer is 48 V. If the primary voltage is 240 V, the turns ratio $N_s/N_p$ is:

a. 1 : 2

b. 1 : 4

c. 1 : 5

d. 1 : 6

Correct answer: c

Explanation:

$$\frac{N_s}{N_p} =\frac{V_s}{V_p} =\frac{48}{240} =\frac15$$

---

MCQ No. 145

A conductor carrying 12 A current is placed at right angles to a magnetic field of 0.5 T. If its length is 0.4 m, the magnetic force is:

a. 1.2 N

b. 2.0 N

c. 2.4 N

d. 3.6 N

Correct answer: c

Explanation:

$$F=BIL =0.5\times12\times0.4 =2.4\text{ N}$$

---

MCQ No. 146

The energy stored in a 6 H inductor carrying a current of 2 A is:

a. 6 J

b. 12 J

c. 18 J

d. 24 J

Correct answer: b

Explanation:

$$U=\frac12LI^2 =\frac12(6)(4) =12\text{ J}$$

---

MCQ No. 147

The inductive reactance of a 2 H inductor at 25 Hz is approximately:

a. 157 Ω

b. 314 Ω

c. 628 Ω

d. 1256 Ω

Correct answer: b

Explanation:

$$X_L=2\pi fL =2\pi(25)(2) \approx314\Omega$$

---

MCQ No. 148

A magnetic flux changes from 1.2 Wb to 0.4 Wb in 0.4 s. The induced emf is:

a. 1 V

b. 2 V

c. 3 V

d. 4 V

Correct answer: b

Explanation:

$$e=\frac{1.2-0.4}{0.4} =\frac{0.8}{0.4} =2\text{ V}$$

---

MCQ No. 149

The magnetic field inside a solenoid having 1000 turns/m carrying 5 A current is approximately:

a. $2.5\times10^{-3}$  T

b. $4.2\times10^{-3}$  T

c. $6.3\times10^{-3}$  T

d. $8.0\times10^{-3}$ T

Correct answer: c

Explanation:

$$B=\mu_0nI$$
$$=4\pi\times10^{-7}\times1000\times5 \approx6.28\times10^{-3}\text{ T}$$

---

MCQ No. 150

An LC circuit has an inductance of 0.25 H and a capacitance of 4 μF. Its resonant frequency is approximately:

a. 80 Hz

b. 159 Hz

c. 318 Hz

d. 500 Hz

Correct answer: b

Explanation:

$$f=\frac{1}{2\pi\sqrt{LC}}$$
$$=\frac{1}{2\pi\sqrt{0.25\times4\times10^{-6}}} \approx159\text{ Hz}$$

---

MCQ No. 151

A rectangular coil of area 0.04 m² having 100 turns is placed in a magnetic field of 0.5 T. If the plane of the coil is perpendicular to the field, the magnetic flux linked with the coil is:

a. 0.5 Wb-turn

b. 1 Wb-turn

c. 2 Wb-turn

d. 4 Wb-turn

Correct answer: c

Explanation:

Flux through one turn,

Φ = BA = 0.5 × 0.04 = 0.02 Wb

Total flux linkage,

NΦ = 100 × 0.02 = 2 Wb-turn

---

MCQ No. 152

A current of 8 A flows through a long straight conductor. Find the magnetic field at 4 cm from the conductor.

a. 2 × 10⁻⁵ T

b. 4 × 10⁻⁵ T

c. 8 × 10⁻⁵ T

d. 1.6 × 10⁻⁵ T

Correct answer: b

Explanation:

$$B=\frac{\mu_0I}{2\pi r}$$
$$=\frac{4\pi\times10^{-7}\times8}{2\pi\times0.04} =4\times10^{-5}\,T$$

---

MCQ No. 153

An electron enters a magnetic field perpendicular to it. If its speed becomes twice, the radius of its circular path becomes:

a. Half

b. Double

c. Four times

d. Same

Correct answer: b

Explanation:

Since

$$r=\frac{mv}{qB}$$

Radius is directly proportional to velocity.

---

MCQ No. 154

The inductive reactance of a 0.5 H inductor connected to 50 Hz AC supply is approximately:

a. 78 Ω

b. 157 Ω

c. 314 Ω

d. 628 Ω

Correct answer: b

Explanation:

$$X_L=2\pi fL$$
$$=2\pi(50)(0.5) \approx157\Omega$$

---

MCQ No. 155

A transformer has 1000 turns in the primary and 250 turns in the secondary. If the primary voltage is 240 V, the secondary voltage is:

a. 30 V

b. 60 V

c. 120 V

d. 240 V

Correct answer: b

Explanation:

$$V_s=V_p\frac{N_s}{N_p} =240\times\frac{250}{1000} =60V$$

---

MCQ No. 156

A charge of 5 C moves with velocity 4 m/s perpendicular to a magnetic field of 0.5 T. The magnetic force is:

a. 5 N

b. 10 N

c. 15 N

d. 20 N

Correct answer: b

Explanation:

$$F=qvB =5\times4\times0.5 =10N$$

---

MCQ No. 157

The energy stored in a 6 H inductor carrying 2 A current is:

a. 6 J

b. 8 J

c. 12 J

d. 24 J

Correct answer: c

Explanation:

$$U=\frac12LI^2 =\frac12(6)(4) =12J$$

---

MCQ No. 158

A conductor of length 0.4 m carrying 5 A current is placed perpendicular to a magnetic field of 0.3 T. The force acting on it is:

a. 0.3 N

b. 0.6 N

c. 0.8 N

d. 1.2 N

Correct answer: b

Explanation:

$$F=BIL =0.3\times5\times0.4 =0.6N$$

---

MCQ No. 159

The RMS current corresponding to a peak current of 14.14 A is:

a. 7.07 A

b. 10 A

c. 14.14 A

d. 20 A

Correct answer: b

Explanation:

$$I_{rms}=\frac{I_0}{\sqrt2} =\frac{14.14}{1.414} =10A$$

---

MCQ No. 160

The capacitance of an LC circuit is increased four times. The resonant frequency becomes:

a. Half

b. Double

c. Four times

d. Same

Correct answer: a

Explanation:

Since

$$f=\frac1{2\pi\sqrt{LC}}$$

If C becomes 4C,

frequency becomes

$$\frac12$$

---

MCQ No. 161

Magnetic flux through a coil changes by 0.8 Wb in 0.2 s. Induced emf is:

a. 1 V

b. 2 V

c. 4 V

d. 8 V

Correct answer: c

Explanation:

$$e=\frac{\Delta\Phi}{\Delta t} =\frac{0.8}{0.2} =4V$$

---

MCQ No. 162

An RL circuit has L = 4 H and R = 2 Ω. The time constant is:

a. 0.5 s

b. 1 s

c. 2 s

d. 4 s

Correct answer: c

Explanation:

$$\tau=\frac LR=\frac42=2s$$

---

MCQ No. 163

The impedance of a series circuit having R = 6 Ω and X = 8 Ω is:

a. 8 Ω

b. 10 Ω

c. 12 Ω

d. 14 Ω

Correct answer: b

Explanation:

$$Z=\sqrt{R^2+X^2} =\sqrt{36+64} =10\Omega$$

---

MCQ No. 164

Power consumed by a circuit with V = 220 V, I = 5 A, and power factor = 0.6 is:

a. 440 W

b. 550 W

c. 660 W

d. 1100 W

Correct answer: c

Explanation:

$$P=VI\cos\phi =220\times5\times0.6 =660W$$

---

MCQ No. 165

The magnetic field inside a solenoid depends directly upon:

a. Radius only

b. Current and turns per unit length

c. Resistance

d. Length only

Correct answer: b

Explanation:

$$B=\mu_0nI$$

---

MCQ No. 166

The unit of magnetic permeability is:

a. T

b. H/m

c. A/m

d. V/m

Correct answer: b

Explanation:

Magnetic permeability is measured in henry per meter (H/m).

---

MCQ No. 167

If the current in a straight conductor becomes three times, the magnetic field becomes:

a. Same

b. Double

c. Triple

d. Nine times

Correct answer: c

Explanation:

Magnetic field is directly proportional to current.

---

MCQ No. 168

The angular frequency corresponding to 60 Hz AC is:

a. 60π rad/s

b. 100π rad/s

c. 120π rad/s

d. 240π rad/s

Correct answer: c

Explanation:

$$\omega=2\pi f =2\pi(60) =120\pi$$

---

MCQ No. 169

The Poynting vector represents:

a. Charge density

b. Electric field

c. Rate of energy flow

d. Magnetic field

Correct answer: c

Explanation:

It gives the power transmitted per unit area.

---

MCQ No. 170

A step-down transformer primarily:

a. Increases voltage

b. Decreases voltage

c. Increases power

d. Increases frequency

Correct answer: b

Explanation:

It converts high voltage into low voltage.

---

MCQ No. 171

An electron moving parallel to magnetic field experiences:

a. Maximum force

b. Minimum force

c. Zero force

d. Infinite force

Correct answer: c

Explanation:

Since θ = 0°,

$$F=qvB\sin0=0$$

---

MCQ No. 172

The magnetic field at the centre of a circular coil increases when:

a. Radius increases

b. Number of turns increases

c. Current decreases

d. Distance increases

Correct answer: b

Explanation:

Magnetic field is directly proportional to the number of turns.

---

MCQ No. 173

The RMS voltage corresponding to a peak voltage of 170 V is:

a. 85 V

b. 100 V

c. 120 V

d. 170 V

Correct answer: c

Explanation:

$$V_{rms}=\frac{170}{1.414}\approx120V$$

---

MCQ No. 174

The magnetic force on a charged particle is always:

a. Parallel to velocity

b. Opposite to velocity

c. Perpendicular to velocity

d. Along acceleration

Correct answer: c

Explanation:

Magnetic force acts at right angles to both the magnetic field and the particle's velocity.

---

MCQ No. 175

Which quantity remains constant when a charged particle moves only under the influence of a magnetic field?

a. Velocity direction

b. Momentum direction

c. Kinetic energy

d. Centripetal force

Correct answer: c

Explanation:

A magnetic force performs no work on a charged particle. Therefore, although the direction of motion changes, its speed and kinetic energy remain constant.

---

MCQ No. 176

A circular coil has 200 turns, radius 0.1 m, and carries a current of 2 A. The magnetic moment of the coil is:

a. 6.28 A·m²
b. 12.56 A·m²
c. 3.14 A·m²
d. 25.12 A·m²

Correct answer: b

Explanation:

$$m=NIA$$

Area,

$$A=\pi r^2=\pi(0.1)^2=0.0314\,m^2$$
$$m=200\times2\times0.0314=12.56\,A\cdot m^2$$

---

MCQ No. 177

The magnetic flux through a surface is 0.6 Wb. If the area is doubled while the magnetic field remains constant, the flux becomes:

a. 0.3 Wb

b. 0.6 Wb

c. 1.2 Wb

d. 2.4 Wb

Correct answer: c

Explanation:

Since

$$\Phi = BA$$

Flux is directly proportional to area.

---

MCQ No. 178

A wire carrying 15 A current is placed in a magnetic field of 0.4 T. A 0.5 m portion is perpendicular to the field. The force on the wire is:

a. 2 N

b. 3 N

c. 4 N

d. 5 N

Correct answer: b

Explanation:

$$F=BIL$$
$$=0.4\times15\times0.5 =3N$$

---

MCQ No. 179

A transformer has 200 turns in the primary and 1000 turns in the secondary. If the primary voltage is 120 V, the secondary voltage is:

a. 240 V

b. 480 V

c. 600 V

d. 300 V

Correct answer: c

Explanation:

$$V_s=V_p\frac{N_s}{N_p}$$
$$=120\times\frac{1000}{200} =600V$$

---

MCQ No. 180

The RMS value of an alternating current is 5 A. The peak current is:

a. 3.54 A

b. 5 A

c. 7.07 A

d. 10 A

Correct answer: c

Explanation:

$$I_0=\sqrt2I_{rms}$$
$$=1.414\times5 =7.07A$$

---

MCQ No. 181

The inductive reactance of a 2 H inductor connected to 25 Hz AC supply is:

a. 157 Ω

b. 314 Ω

c. 628 Ω

d. 785 Ω

Correct answer: b

Explanation:

$$X_L=2\pi fL$$
$$=2\pi\times25\times2 =314\Omega$$

---

MCQ No. 182

An inductor stores 18 J of energy while carrying a current of 3 A. The inductance of the coil is:

a. 2 H

b. 3 H

c. 4 H

d. 5 H

Correct answer: c

Explanation:

$$U=\frac12LI^2$$
$$18=\frac12L(9)$$
$$L=4H$$

---

MCQ No. 183

An electron enters a 0.02 T magnetic field with velocity 3 × 10⁶ m/s perpendicular to the field. The magnetic force is approximately:

a. $4.8\times10^{-15}$  N

b. $9.6\times10^{-15}$  N

c. $1.6\times10^{-19}$  N

d. $3.2\times10^{-15}$  N

Correct answer: b

Explanation:

$$F=qvB$$
$$=(1.6\times10^{-19})(3\times10^6)(0.02) =9.6\times10^{-15}N$$

---

MCQ No. 184

The magnetic field inside a long solenoid becomes double when:

a. Radius is doubled

b. Length is doubled

c. Current is doubled

d. Resistance is doubled

Correct answer: c

Explanation:

$$B=\mu_0nI$$

Magnetic field is directly proportional to current.

---

MCQ No. 185

If the frequency of AC is doubled, the inductive reactance becomes:

a. Half

b. Same

c. Double

d. Four times

Correct answer: c

Explanation:

$$X_L=2\pi fL$$

Therefore,

$$X_L\propto f$$

---

MCQ No. 186

The capacitive reactance of a capacitor decreases when:

a. Frequency decreases

b. Frequency increases

c. Capacitance decreases

d. Resistance increases

Correct answer: b

Explanation:

$$X_C=\frac1{2\pi fC}$$

Higher frequency gives lower reactance.

---

MCQ No. 187

An RL circuit has L = 6 H and R = 3 Ω. The time constant is:

a. 1 s

b. 2 s

c. 3 s

d. 6 s

Correct answer: b

Explanation:

$$\tau=\frac LR=\frac63=2s$$

---

MCQ No. 188

A charge moves in a magnetic field at an angle of 90°. The magnetic force is:

a. Zero

b. Minimum

c. Maximum

d. Half maximum

Correct answer: c

Explanation:

Since

$$F=qvB\sin\theta$$

and

$$\sin90^\circ=1$$

force is maximum.

---

MCQ No. 189

A conductor moves across magnetic field lines. The induced emf depends on:

a. Speed only

b. Magnetic field only

c. Length only

d. All of these

Correct answer: d

Explanation:

$$e=BLv$$

It depends on magnetic field, conductor length, and speed.

---

MCQ No. 190

The frequency of an LC circuit becomes half when:

a. L becomes four times

b. C becomes one-fourth

c. Both L and C become half

d. L becomes one-fourth

Correct answer: a

Explanation:

Since

$$f\propto\frac1{\sqrt{LC}}$$

Increasing inductance four times halves the frequency.

---

MCQ No. 191

Power consumed by an AC circuit having 230 V, 10 A, and power factor 0.5 is:

a. 575 W

b. 920 W

c. 1150 W

d. 2300 W

Correct answer: c

Explanation:

$$P=VI\cos\phi$$
$$=230\times10\times0.5 =1150W$$

---

MCQ No. 192

The magnetic permeability of vacuum is approximately:

a. $2\pi\times10^{-7}$

b. $4\pi\times10^{-7}$

c. $8\pi\times10^{-7}$

d. $10^{-6}$

Correct answer: b

Explanation:

$$\mu_0=4\pi\times10^{-7}\;H/m$$

---

MCQ No. 193

If the number of turns of a transformer is doubled while keeping the turns ratio unchanged, the output voltage will:

a. Double

b. Become half

c. Remain unchanged

d. Become zero

Correct answer: c

Explanation:

Transformer voltage depends on the turns ratio, not the absolute number of turns.

---

MCQ No. 194

An AC source has a frequency of 100 Hz. Its time period is:

a. 0.1 s

b. 0.02 s

c. 0.01 s

d. 0.005 s

Correct answer: c

Explanation:

$$T=\frac1f=\frac1{100}=0.01s$$

---

MCQ No. 195

The magnetic field at the center of a circular coil becomes double when:

a. Radius is doubled

b. Current is halved

c. Current is doubled

d. Radius is tripled

Correct answer: c

Explanation:

Magnetic field is directly proportional to current.

---

MCQ No. 196

The magnetic force on a moving charged particle is always directed:

a. Along the magnetic field

b. Opposite to velocity

c. Perpendicular to both velocity and magnetic field

d. Along the electric field

Correct answer: c

Explanation:

The direction of magnetic force is determined by the cross product q(v × B).

---

MCQ No. 197

Which device is based on electromagnetic induction?

a. Transformer

b. Electric heater

c. Rheostat

d. Voltmeter

Correct answer: a

Explanation:

A transformer works by mutual induction according to Faraday's law.

---

MCQ No. 198

The SI unit of inductive reactance is:

a. Henry

b. Tesla

c. Ohm

d. Weber

Correct answer: c

Explanation:

Reactance is a type of opposition to AC and is measured in ohms (Ω).

---

MCQ No. 199

A current-carrying conductor experiences no magnetic force when the angle between the current and magnetic field is:

a. 30°

b. 45°

c. 60°

d. 0°

Correct answer: d

Explanation:

$$F=BIL\sin\theta$$

When θ = 0°, sin0° = 0, so the force is zero.

---

MCQ No. 200

A moving charge enters a uniform magnetic field and follows a circular path. This shows that the magnetic force acts as:

a. Gravitational force

b. Electrostatic force

c. Centripetal force

d. Frictional force

Correct answer: c

Explanation:

The magnetic force is always perpendicular to the velocity of the charged particle and provides the necessary centripetal force for circular motion.

---

📚 Continue Your Physics Preparation

If you found this quiz helpful, explore our complete collection of Physics learning resources.

🔬 Physics MCQs Hub

---

More Study Resources for Students and Teachers

• Computer Science 11th Class Notes (Main Page) 
• Computer Science 12th Class Notes (Main Page) 

************************************

1. English Poems Analysis Hub– A to Z Index (English Poetry) 

(https://poemanalysishub.blogspot.com/p/english-poems-analysis-to-z-index.html)

2. Website for School and College Level Mathematics  

(https://askraremaths.blogspot.com)

3. ASK Rare Class Notes – Study Resources for Students & Teachers 

(https://askrareclassnotes.blogspot.com/)

© 2026 & onwards Academic Skills and Knowledge (ASK)   

Note:  Write me in the comments box below for any query and also Share this information with your classmates and friends.

---

© https://askrareclassnotes.blogspot.com | Learn • Practice • Succeed

---

Best Tools and Supplies for Students and Teachers:

📚 Grammar Books – Improve Writing, Score Higher
🪑 Study Chairs – Sit Comfortably, Study Better
🛋️ Study Desks – Organized Space, Better Learning
💡 Desk Lamps – Bright Light, Better Focus
⌚ Digital Watches– Manage Time, Improve Results
📱 Phone Stands – Hands-Free Learning Made Easy
🎧 Headphones – Focus Better, Learn Without Distractions
⌨️ Wireless Keyboards – Type Faster, Work Smarter
🖱️ Wireless Mouse – Smooth Control, Better Workflow
🖨️ Printers – Print Smart, Save Time

Disclosure: The above links on this page are affiliate links. This means that if you make a purchase through them, I may earn a small commission at no additional cost to you. Your support helps me maintain, improve, and continue providing valuable free content on this website.

With Best Regards

ASKRare Team

---

---

🌍📖

"Knowledge grows when it is shared."

At ASK Rare Class Notes, we believe quality education should be freely accessible to everyone. Learn, share, inspire, and help others succeed.