Abhi koi question add nahi kiya. PYQ Bank se questions add karein.
PYQ Bank ›
Class 12 › Physics › Moving Charges and Magnetism
CBSE2022Class Class 12 · Physics3 Marks · Short✅ Verified
A solenoid is 2.0 m long and 8.0 cm in diameter. It has 5 layers of winding of 1000 turns each and carries a current of 5.0 A. What is the magnetic field at its centre? ($\mu_0 = 4\pi \times 10^{-7}$ T·m/A)
✅ Answer & Solution
Total turns $N = 5 \times 1000 = 5000$
Length $L = 2.0$ m
Turns per metre: $n = N/L = 5000/2 = 2500$ turns/m
Magnetic field at centre of solenoid:
$$B = \mu_0 nI = 4\pi \times 10^{-7} \times 2500 \times 5.0$$
$$B = 4\pi \times 10^{-7} \times 12500 = 4\pi \times 1.25 \times 10^{-3}$$
$$B = 5\pi \times 10^{-3} \approx 1.571 \times 10^{-2} \text{ T} \approx 0.0157 \text{ T}$$
