A straight wire having mass of 1.2 kg and length of 1 m carries a current of 5 A. If the wire is suspended in mid-air by a uniform horizontal magnetic field, then the magnitude of field is

Question

A straight wire having mass of 1.2 kg and length of 1 m carries a current of 5 A. If the wire is suspended in mid-air by a uniform horizontal magnetic field, then the magnitude of field is (A) 0.65 T (B) 1.53 T (C) 2.4 T (D) 3.2 T

Tardigrade Admin · Accepted Answer

For mid-air suspension the upward force

F

on wire due to magnetic field

B

must be balanced by the force due to gravity, then

I lB = m g; B = \frac{m g}{I l}

Here,

m = 1.2 k g

,

g = 10 m s^{- 2}, I = 5 A

,

l = 1 m

B = \frac{1.2 \times 10}{5 \times 1}

= 2.4 T

Q. A straight wire having mass of $1.2 k g$ and length of $1 m$ carries a current of $5 A$ . If the wire is suspended in mid-air by a uniform horizontal magnetic field, then the magnitude of field is

$0.65 T$

$1.53 T$

$2.4 T$

$3.2 T$

For mid-air suspension the upward force $F$ on wire due to magnetic field $B$ must be balanced by the force due to gravity, then
$I lB = m g; B = \frac{m g}{I l}$
Here, $m = 1.2 k g$ ,
$g = 10 m s^{- 2}, I = 5 A$ ,
$l = 1 m$
$B = \frac{1.2 \times 10}{5 \times 1}$
$= 2.4 T$

Q. A straight wire having mass of 1.2kg and length of 1m carries a current of 5A. If the wire is suspended in mid-air by a uniform horizontal magnetic field, then the magnitude of field is

0.65T

1.53T

2.4T

3.2T