Question

(a) In premises 4 bulbs each of 100 W, 4 fans each of 60 W, 2 air conditioners each of

1.5 kW are used for 5 hours per day. Find:

(i) Total power consumed per day.

(ii) Total power consumed in 30 days.

(iii) Total electrical energy consumed in 30 days.

(iv) The cost of electricity at a rate of Rs 10 per unit

(b) Two waves have frequencies 100Hz and 400Hz, but same amplitude. Compare

their (i) loudness (ii) pitch



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Answer 1

Answer:

Power consumed by

5 bulbs = 5 × 100 = 500 W

2 fans = 2 × 60= 120 W

2 A.C = 2 × 1.5 x 1000 = 3000 W

(a) Total power consumed per day = 3620 W

(b) Total power consumed in 30 days = 3620/1000 × 30 = 108.6 kw

(c) Electric energy is used for 5 h per day.

Total electrical energy consumed in 30 days.

(d) Cost of electricity = P × t = 108.6 × 5 = 543 kWh

= 543 × 6.25 = Rs 3393.75

this is your answer dear