Solveeit Logo
Login

Question

Question: A rectangular coil ABCD is hung from one side of a balance as shown in figure. A 500 g mass is added...

A rectangular coil ABCD is hung from one side of a balance as shown in figure. A 500 g mass is added to the other arm to balance the weight of the coil. A current of 9.8 A is passed through the coil and a constant magnetic field of 0.4 T acting inward (in xz plane) is switched on such that only arm CD of length 1.5 cm lies in the field. The additional mass m must be added to regain the balance is

A

4 g

B

5 g

C

6 g

D

7 g

Answer

6 g

Explanation

Solution

In absence of magnetic field the weight added in one pan balances the rectangular coil in the other pan of balance,

∴\therefore or Wcoil =Mg=0.5×9.8 N\mathrm { W } _ { \text {coil } } = \mathrm { Mg } = 0.5 \times 9.8 \mathrm {~N}

When current I is passed through the coil and the magnetic field is switched on

Let m mass added in the first pan to regain the balance then

Or

=6×10−3 kg=6 g= 6 \times 10 ^ { - 3 } \mathrm {~kg} = 6 \mathrm {~g}