Question

A winding wire which is used to frame a solenoid can bear a maximum of 20 A current. If the length of the solenoid is 80 cm and its cross-sectional radius is 3 cm, then the required length of winding wire is ______ (B = 0.2 T)

पर्याय

• 1.2 x 10² m

• 4.8 x 10² m

• 2.4 x 10³ m

• 6 x 10³ m

Answer 1

A winding wire which is used to frame a solenoid can bear a maximum of 20 A current. If the length of the solenoid is 80 cm and its cross-sectional radius is 3 cm, then the required length of winding wire is 1.2 x 10² m.

Explanation:

 B = `(mu_0"ni")/l`

∴ 0.2 = `(4pi xx 10^-7 xx "n" xx 20)/0.8`

∴ n = `(2 xx 10^4)/pi`

Since n turns are made from the winding wire, so the length of the wire (L)

= 2πr x n [2πr = length of each turn]

∴ L = `2pi xx 3 xx 10^-2 xx (2 xx 10^4)/pi`

= `1.2 xx 10^2` m