NEET Magnetic Effects of Current and Magnetism — Set 7

Question 1

A solenoid with 2500 turns per meter carries a current of $ 2 \, \text{A} $. What is the magnetic field inside it? ($ \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} $)

Accepted Answer

Magnetic field $ B = \mu_0 n I $. $ B = 4 \pi \times 10^{-7} \times 2500 \times 2 = 20 \pi \times 10^{-4} \approx 6.28 \times 10^{-3} \, \text{T} $.

Question 2

A solenoid with 1600 turns per meter carries a current of $ 2 \, \text{A} $. What is the magnetic field inside it? ($ \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} $)

Accepted Answer

Magnetic field $ B = \mu_0 n I $. $ B = 4 \pi \times 10^{-7} \times 1600 \times 2 = 12.8 \pi \times 10^{-4} \approx 4.02 \times 10^{-3} \, \text{T} $.

Question 3

A rectangular loop of area $ 0.05 \, \text{m}^2 $ with 15 turns carries $ 2 \, \text{A} $ in a field of $ 1 \, \text{T} $ at $ 90^\circ $ to the plane. What is the torque?

Accepted Answer

$ \tau = N I A B \sin \theta $, $ \theta = 90^\circ $ to plane means $ \sin 0^\circ = 1 $ with normal. $ \tau = 15 \times 2 \times 0.05 \times 1 \times 1 = 1.5 \, \text{N m} $.

NEET Physics: Magnetic Effects of Current and Magnetism — Practice Set 7

Q1. A solenoid with 2500 turns per meter carries a current of \( 2 \, \text{A} \). What is the magnetic field inside it? (\( \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} \))

Q2. A solenoid with 1600 turns per meter carries a current of \( 2 \, \text{A} \). What is the magnetic field inside it? (\( \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} \))

Q3. A rectangular loop of area \( 0.05 \, \text{m}^2 \) with 15 turns carries \( 2 \, \text{A} \) in a field of \( 1 \, \text{T} \) at \( 90^\circ \) to the plane. What is the torque?

Q4. A rectangular loop of area \( 0.08 \, \text{m}^2 \) with 15 turns carries \( 2.5 \, \text{A} \) in a field of \( 0.6 \, \text{T} \) at \( 30^\circ \) to the plane. What is the torque?

Q5. What is the primary function of the shunt resistance in converting a galvanometer to an ammeter?

Q6. A straight wire of length \( 1.4 \, \text{m} \) carries a current of \( 3 \, \text{A} \) perpendicular to a uniform magnetic field of \( 0.35 \, \text{T} \). What is the force on the wire?

Q7. A wire of length \( 1.7 \, \text{m} \) carrying \( 7 \, \text{A} \) is at \( 60^\circ \) to a magnetic field of \( 0.2 \, \text{T} \). What is the force on the wire?

Q8. A long wire carries \( 16 \, \text{A} \). At what distance is the magnetic field \( 8 \times 10^{-6} \, \text{T} \)? (\( \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} \))

Q9. A straight wire of length \( 1.5 \, \text{m} \) carries a current of \( 6 \, \text{A} \) perpendicular to a uniform magnetic field of \( 0.25 \, \text{T} \). What is the force on the wire?

Q10. A circular loop of radius \( 0.14 \, \text{m} \) with 15 turns carries a current of \( 4 \, \text{A} \). What is the magnetic field at the center? (\( \mu_0 = 4 \pi \times 10^{-7} \, \text{T m/A} \))