Two bulbs of 500 watt and 200 watt are manufactured to operate on 220 volt line. The ratio of heat produced in `500 W` and `200 W`, in two cases, when firstly they are joined in parallel and secondly in series, will be

Options

A. `(5)/(2) : (2)/(5)`
B. `(5)/(2): (5)/(2)`
C. `(2)/(5): (5)/(2)`
D. `(2)/(5) : (2)/(5)`

Answer

A

Explanation

In parallel, `(H_1)/( H_2)= ( P_1 t)/( P_2 t) =(P_1)/( P_2) = (500)/( 200) = (5)/(2)`
in series, `(H_1)/(H_2)= (I^2 R_1 t)/(I^2 R_2 t) = (R_1)/( R_2) = (V^(2) // P_(1))/( V^(2) // P_(2))= (P_2)/( P_1) = (200)/( 500) =(2)/(5)`.