Question

20. There are two electrical devices, one is electrical kettle of 2KW-200V and

next one is electrical heater of 1KW-240 V. Which device has highest
resistance?
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Answer 1

Electrical kettle:

P = 2 KW = 2000 W

U = 200 V

⇒ I = P/U = 2000 / 200 = 10 A

We apply the Law of Ohm:

R = U / I = 200V / 10A = 20 Ω

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Electrical heater:

P = 1 KW = 1000 W

U = 240 V

⇒ I = P/U = 1000 / 240 = 4,16 A

We apply the Law of Ohm:

R = U / I = 240V / 4,16A = 57,69 Ω

Answer:

The device with the highest resistance is the electric heater.

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