Question

A bulb is rated at 200v 40w what is it resistance 5 such bulbs are lighted

Answer 1

$\huge \boxed{answer}$

V = 200 V, P = 40 W

P = V × I

I = P / V

= 40 / 200

= 1 / 5 A

R = V / I

= 200 / ( 1/5 )

= 200 × 5

= 1000 ohm

Total power = 40W × 5

= 200 Wh

Time = 5 hours

Electrical energy = 200W × 5 hours

= 1000 Wh

= 1 kWh

Cost of 1 kWh = Rs. 5.10

$\huge \mathfrak \red{hope \: it \: helps \: u}$