Unit of radioactivity is:

(A) Pascal

(B) Energy

(C) Angstran

(D) Becquerels

Answer: (D) Becquerels

A material’s radioactivity is measured in becquerels (Bq, international unit).

If two identical circular loops “Y” and “Z” of a metal wire are placed on a table without touching each other. Loop “y” carries a current which increases with time. In response, the loop “Z” will:

(A) Remain Stationary
(B) Be attracted by loop “Y”
(C) Be repelled by loop “Y”
(D) Rotate about centre of mass

Answer: (C) Be repelled by loop “Y”
If two identical circular loops “Y” and “Z” of a metal wire are placed on a table without touching each other. Loop “y” carries a current which increases with time. In response, the loop “Z” will be repelled by loop “Y”.