Question

An electrical heater of resistance 8 ohm draws 15 a from the service mains 2 hours calculate rate at which heat is developed in the heater

Answer 1

Answer:

12960 kJ

Explanation:

According to the given question,

I = Current = 15 A

R = Resistance = 8 ohm

t = time = 2 h = 2×60×60 = 7200 sec

H = Heat developed

And we are asked to find the heat developed in the electrical heater.

We know,

• H = I^2 ×R × t

Putting the values we get,

• H = 15^2 × 8 × 7200

• H = 12960,000 J

• H = 12960 kJ

Thus heat developed in the electrical heater is 12960 kJ from the given data.

Answer 2

Answer=12960kj

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Formula used :-

H= I^2 *R*T

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Step by step explanation

Resistance (R) = 8 ohm .........(1)

Current (I) = 15 A.........(2)

Time = 2 hrs( convert it to seconds) 2*3600

=7200sec.......

H ( Heat energy ) = I ^2 (R)(T)

= (15)^2*8*7200

H= 12960000 joule (j)

H = 12960 kilo joule (kj)