Q.1

The resistance of a wire is 10W. Its length is increased by 10% by stretching. The new resistance will now be nearly

(a)  12 W           

(b) 1.2 W             

(c) 13 W           

(d) 11 W

Ans :  (a)

Q.2

The same mass of copper is drawn into two wires 1 mm and 2 mm thick. Two wires are connected in series and current is passed through them. Heat produced in the wire is in the ratio

(a)  2 : 1           

(b)  1 : 16                 

(c)  4 : 1                 

(d) 16 : 1

Ans :   (d)