Question

Hello Guys

Please give the solution of this 10 standard question

Q) 2 electric bulbs rated 100W;220V and 60W;220V are connected in parallel to an electric mains of 220V. Find the current drawn by the bulbs from the mains.

Answer 1

Answer:

Plus karke ans niklega is question ka

Answer 2

Power = P = 100 W

Voltage = V = 220v

Resistance = R

P = V²/R

100 = 220 ×220/R

R = 220 × 220/100

= 484 Ω

Power = P = 60 W

Voltage = V = 220v

Resistance = R

P = V²/R

60 = 220 × 220/R

R = 220× 220/60

= 806.7

As the resistors are connected in parallel ,

total resistance = 1/R

1/R = 1/484 + 1/806.7

= 806.7 + 484/484×806.7

= 1290.7/390442.8

R = 390442.8/ 1290.7 = 302.5 ohms

Total resistance = 302.5 Ω

I = current

V = IR

220 = I × 302.5

I = 220/302.5

= 0.73 A

The current drawn is 0.73 A