Question

A 20 V - 5 W lamp is to run on 200 V- 50 Hz a.c. mains. Find the capacitance of a capacitor required to run the lamp.

Answer 1

Answer:

lamp is run on 200v capacitor transistor and a transformer

Answer 2

Answer:

25 micro farad

Explanation:

we know, P= VI

so maximum current followed by the lamp is

I =P/V= 5/20= 0.25AMP

SO this max current need to supply by the AC source

so, we have a relation for max current flow in AC circuit in which a capacitor are present

I=Vac/(1/wC) = 200/(1/50*C)

by conditions, 0.25=200/(1/50*C)

:. C= 0.25/(200*50)=25*10^-6 farad= 25 micro farad