Question

5 bilb each rated as 220 voltage 100 watt bulb 4 hour.what is the cost of electricity consumed if the rate each 50 paisa per unit

Answer 1

Formula electric appliance
P = V² /R
or we can written as

R = V² / P

now, here
P = 100 W
V = 200 volts
So
R = 200² / 100
= 40000 / 100
================================
thus, resistance of the bulb is R = 400 Ω

now, electric energy consumed will be
E = number of units x power of each unit x time = n x P x t
=================================
Given
n = 5
P = 100 W
t = 4 hours
Then so
E = 5 x 100 x 4

thus, E = 2000 Wh = 2 kWh

total cost of electricity = total unit of energy consumed x cost per unit
= 2kWh x 0.5 Rs/kWh
thus,
total cost (daily) = Rs. 1
& Monthly cost is 30× 1 =30Rs

Hope it's helpful ☺✌