Question

Question 4.8: A closely wound solenoid 80 cm long has 5 layers of windings of 400 turns each. The diameter of the solenoid is 1.8 cm. If the current carried is 8.0 A, estimate the magnitude of B inside the solenoid near its centre.

Class 12 - Physics - Moving Charges And Magnetism Moving Charges And Magnetism Page-169

Answer 1

total number of turns in 80cm length of solenoid can be calculated as N = number of layers × number of turns on each layer.
= 5 × 400 = 2000 turns
so, number of turns per unit length , n = 2000/80 × 10^-2 = 2500 turns/m

so, magnetic field near the centre of long solenoid is $B=\mu_0nI$
so, B = 4π × 10^-7 × 2500 × 8
B = 8π × 10^-3 T

Answer 2

Answer:

here is the answer for you dear