Question

An electric oven of resistance 2 ohm draws a current of 20 A.it works 8 hours daily calculate the weekly bill when energy cost rupees 3.20 per unit

Answer 1

V = I R

= 20 * 2 = 40 Volt.

Power =V * I

= 40 * 20

= 800 W

Energy consumed = 800 * 8 = 6400 W = 6.4Kwh

Cost = 3. 20 * 6.4*7
= 20.48 * 7
= 143.36

Answer 2

i = 20A

r = 2 ohm

V = i × r

= 20 × 2 = 40V

P = V × i

= 40 × 20

P = 800 W

It works 8 hr daily so in week it will work

8 × 7 = 56 hr

It wil consume 800 × 56 = 44800 W

44.8 kW

If cost of per unit is 3.20 then cost of 44.8 unit is

= 44.8 × 3.20

= 143.36 Rs

Thanks