Magnetism and EMI Practice Questions
JEE · Physics · 1523 free MCQs with instant results and detailed explanations.
1523
Total
372
Easy
694
Medium
457
Hard
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Topics in Magnetism and EMI
Ampere's Law
408
Biot-Savart Law
445
Faraday's Law
316
AC Circuits
354
Sample Questions from Magnetism and EMI
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What does the Biot-Savart Law describe?
A.
Magnetic field due to a steady current
B.
Electric field due to a steady charge
C.
Magnetic flux through a surface
D.
Induced EMF in a closed loop
Show Answer & Explanation
Correct Answer: A
The Biot-Savart Law specifically describes how electric currents produce magnetic fields.
Q2
Easy
If a current-carrying wire is bent into a circular loop, what is the direction of the magnetic field at the center of the loop?
A.
Perpendicular to the plane of the loop
B.
Parallel to the plane of the loop
C.
In the direction of the current
D.
Opposite to the direction of the current
Show Answer & Explanation
Correct Answer: A
According to the right-hand rule, the magnetic field at the center of a circular loop is perpendicular to the plane of the loop.
Q3
Easy
According to the Biot-Savart Law, how does the magnetic field strength change with distance from a straight current-carrying wire?
A.
Increases linearly with distance
B.
Decreases with the square of the distance
C.
Increases with the square of the distance
D.
Remains constant
Show Answer & Explanation
Correct Answer: B
The magnetic field around a straight current-carrying wire decreases inversely with distance from the wire.
Q4
Medium
A circular loop of radius 0.1 m carries a current of 5 A. Calculate the magnetic field at the center of the loop using the Biot-Savart Law. (Use \( \mu_0 = 4\pi \times 10^{-7} \, Tm/A \))
A.
1.0 × 10⁻⁵ T
B.
2.0 × 10⁻⁵ T
C.
4.0 × 10⁻⁵ T
D.
8.0 × 10⁻⁵ T
Show Answer & Explanation
Correct Answer: A
The magnetic field at the center of a circular loop is given by \( B = \frac{\mu_0 I}{2R} \). Here, \( I = 5 A \) and \( R = 0.1 m \). Thus, \( B = \frac{4\pi \times 10^{-7} \times 5}{2 \times 0.1} = 1.0 \times 10^{-5} T \).
Q5
Medium
Two parallel long wires, separated by a distance of 0.5 m, carry currents of 3 A and 5 A in the same direction. What is the magnitude of the magnetic field at a point midway between them?
A.
3.0 × 10⁻⁶ T
B.
4.0 × 10⁻⁶ T
C.
7.0 × 10⁻⁶ T
D.
8.0 × 10⁻⁶ T
Show Answer & Explanation
Correct Answer: C
The magnetic field due to each wire at the midpoint is calculated separately and then summed. For wire 1 (3 A), B1 = \( \frac{\mu_0 * I1}{2π * 0.25} \) and for wire 2 (5 A), B2 = \( \frac{\mu_0 * I2}{2π * 0.25} \). The total field is the difference since they are in the same direction.
Q6
Medium
In a circular loop of radius R carrying a current I, what is the magnetic field at the center of the loop?
A.
(μ₀I)/(2R)
B.
(μ₀I)/(4πR)
C.
(μ₀I)/(2πR)
D.
(μ₀I)/(R)
Show Answer & Explanation
Correct Answer: C
The magnetic field at the center of a circular loop is given by B = (μ₀I)/(2R).
Q7
Medium
What is the direction of the magnetic field produced by a straight current-carrying conductor?
A.
In the direction of current
B.
Opposite to the direction of current
C.
Perpendicular to the current
D.
None of the above
Show Answer & Explanation
Correct Answer: C
The magnetic field produced by a straight conductor is perpendicular to the direction of the current, according to the right-hand rule.
Q8
Hard
A long straight wire carrying a current of 5 A is placed along the z-axis. What is the magnetic field at a point 0.1 m away on the x-axis?
A.
1 × 10^-5 T
B.
2 × 10^-5 T
C.
4 × 10^-5 T
D.
8 × 10^-5 T
Show Answer & Explanation
Correct Answer: C
Using the Biot-Savart law, the magnetic field due to a straight current-carrying wire at a distance 'r' is given by B = (μ₀I)/(2πr). Here, μ₀ = 4π × 10^-7 T m/A, I = 5 A, and r = 0.1 m. Calculating gives B = 4 × 10^-5 T.
Q9
Hard
A circular loop of radius 0.1 m carries a current of 10 A. What is the magnetic field at its center?
A.
2 × 10^-5 T
B.
4 × 10^-5 T
C.
8 × 10^-5 T
D.
1 × 10^-5 T
Show Answer & Explanation
Correct Answer: B
The magnetic field at the center of a circular loop is given by B = (μ₀I)/(2r). Substituting μ₀ = 4π × 10^-7 T m/A, I = 10 A, and r = 0.1 m results in B = 4 × 10^-5 T.
Q10
Hard
A wire bent into the shape of a semicircle of radius 0.2 m carries a current of 5 A. What is the magnetic field at the center of the semicircle?
A.
2.5 × 10^-5 T
B.
5 × 10^-5 T
C.
3.2 × 10^-5 T
D.
4 × 10^-5 T
Show Answer & Explanation
Correct Answer: A
The magnetic field due to a semicircular wire is B = (μ₀I)/(4r). For I = 5 A and r = 0.2 m, B calculates to 2.5 × 10^-5 T.
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Magnetism and EMI — JEE Physics Practice Questions Online
This page contains 1523 practice MCQs for the chapter Magnetism and EMI in JEE Physics. The questions are organized by difficulty — 372 easy, 694 medium, 457 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 4 topics, giving you comprehensive coverage of the entire chapter.