A straight wire of lengt 2m is kept horizontla in a uniform magnetic field of induction `4xx10^(-3)Wb//m^(2).` The field is horizontal and is at right angles to the length of the conductor. It is found that the conductor remains balanced, if a current of 4.9 A is passed through the conductor. What is the mass of the wire ?

Options

A. 4 gram
B. 5 gram
C. 6 gram
D. 8 gram

Answer

A

Explanation

The force acting on the conductor =Bil
Since F balances the weight mg
`therefore Bil =mg`
`therefore m = (BIl)/(g ) =( 4xx10^(-3) xx4.9 xx2)/(9.8)`
`therefore m=4 xx 10^(-3) kg =4 gram`