1.

Find the value of resistance connected in a series with a bulb 60watt, 30 volt to run on 90volt supply

Answer»

Explanation:

resistance of is

P = V²/ R

R = V²/P = ( 30x 30)/60 = 15 ohm

if applied VOLTAGE is 90v

then pd across bulb is

V = IR

30 = I X 15

I = 30/15 = 2A

thus pd across a resistor which is connected with bulb in order to DROP only 30 v across bulb.

V = I x r

60 = 2 x r

r = 30OHM



Discussion

No Comment Found

Related InterviewSolutions