Question

At a given time, a house is supplied with 100 A at 220 V. How many 75 W, 220 V light bulb could be switched on in the house at the same time (if they are all connected in parallel)?

Options

• 93

• 193

• 293

• 393

Answer 1

293

Explanation:

Total power provided in the house,

 P = VI = `100  "A" xx 220  "V"` = 22000 W

This is the maximum power that can be drawn in the house.

Total power drawn by x bulbs = 75x W

∴ Maximum power x bulbs can draw = 22000 W 

⇒ 75x = 22000`

⇒ x = `22000/75~~293`