Question

Q5. A solenoid of length 100 cm is wound uniformly with 10 000 turns

Answer 1

Answer:

i) 0.05 T

ii) 0.025 T

Explanation:

current I = 4 A

length of solenoid L = 100 cm = 1 m

number of turns N = 10000 turns

number of turns per unit length n = N/L = 10000/1 = 10000 turns/meter

i) magnetic field on the axis of the solenoid at the center

B = μ$nI$

where μ is vacuum permeability = 4π×10−7 H/m = 1.256 x $10^{-6}$ H/m

B =  1.256 x $10^{-6}$ x  10000 x 4 = 0.05 T

ii) magnetic field on the axis at the end will be equal to

B = (μ$nI$) ÷ 2

this is based on the assumption that the length of the solenoid is far greater than than the diameter of the solenoid. Therefore,

B = 0.05 ÷ 2 = 0.025 T