Q. 95.0( 4 Votes )
For a heater rated at 4 kW and 220 V, calculate:
(a) the current,
(b) the resistance of the heater,
(c) the energy consumed in 2 hours, and
(d) the cost if 1 kWh is priced at ₹ 4.60
(a) Here, P = 4kw, V = 220v
I = ?
We know that
Power = VI = 220 × I
4000 = 220I
I = 4000/220= 18.18A
(b) Here, P = 4kw, V = 220v
R = ?
We know that,
P = I2R
P = (18.18)2×R
R = 4000/(18.18)2
R = 12.10 Ω
(c) Here, P = 4kw, time = 2hr
Energy consumed in two hour = P × t
= 4 × 2
(d) If 1kwh = Rs 4.6
Here, Energy consumed in two hour = 8kwh
So, total cost = 8 x 4.6 = Rs 36.8
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