Question

An ideal solenoid of length 10 cm consists of a wire wrapped tightly around a wooden core. The magnetic field strength is 4.0 T inside the solenoid. If the solenoid is stretched to 25 cm by applying a force to it, what does the magnetic field become

Answer 1

Answer:

The magnetic field will become 1.6 T.

Explanation:

Given;

initial length of the solenoid, L₁ = 10 cm

final length of the solenoid, L₂ = 25 cm

Magnetic field inside a solenoid is given by;

$B = \frac{\mu_o NI}{L} \\\\BL =\mu_oNI = k\\\\BL = k\\\\B_1L_1 = B_2L_2\\\\B_2 = \frac{B_1L_1}{L_2}\\\\B_2 = \frac{4*10}{25}\\\\B_2 = 1.6 \ T$

Therefore, the magnetic field will become 1.6 T.