Question

Resistances of two lamps are in the ratio 4:5. How and which of the following is the ratio of their powers when operated on the same voltage
A.4:5. B.5:4. C.16:25
D.25:16

Answer 1

$\huge\bold{\red{ANSWER}}$

(b) 5:4

Explain:-

R1/R2=4:5

THE VOLTAGE IS SAME

P1/P2=V^2/R1/V^2/R2

=R2/R1

=5/4

SINCE

P1:P2=5:4