Two electric bulbs rated `25 W , 220 V and 100 W , 220 V` are connected in series across a `220 V` voltage source . The `25 W and 100 W` bulbs now draw `P_(1) and P_(2)` powers , respectively.

Options

A. (i),(iv)
B. (ii), (iii)
C. (i), (iii)
D. all

Answer

A

Explanation

`R_(1) = ((220)^(2))/(25) = 4R, R_(2)=((220)^(2))/(100) =R`
`V_1 = (4R)/(4R+R) xx 220 = 4/5xx220 V`
`V_(2)= 220-V_(1) = 1/5xx220V`
`P_(1) = (V_1^2)/(R_1) = ((4//5)^(2)(220)^(2))/((220)^(2)//25) = 16W`
`P_(2) = (V_2^2)/(R_2) = ((1//5)^(2)(220)^(2))/((220)^(2)//100) = 4W`.