Question

please answer it please​

Answer 1

Explanation:

Given :-

Volt = 220 V

Power = 40W

Cost = ₹ 5.10/unit

No of such bulb = 5

Time lighted = 5 hrs

we know that ,

P = V²/R

40 = 220*220/R

R = 220*220/40

R = 1210 Ω

Since, each bulb has 40 W power .

So such 5 bulbs will have power = 40*5 = 200 W

We also know that ,

Energy consumed = P*t

= 200*5

= 1000/1000

= 1 unit

Hence ,cost = ₹ 5.10*1 = ₹ 5.10