Question

An Electric Iron of resistance 42 Ohm takes a current of 5 A.Calculate Heat in calories developed in 30 s.. (W= JH )..Given Answer is 7500 calories but How ????

Answer 1

H = I²Rt

here,

I = 5 amps

R = 42 ohms

t = 30 s

so,

H = 52 x 42 x 30

or

H = 31500 Joules

now, we have to convert the above into units of calories

we know that

1 Joule = 0.239 Calories

so,

H = 0.239 x 31500 calories

or

H = 7528.5 calories ~ 7500 calories

Answer 2

Answer:

The above solution of your question is 100% right

don't need to worry

you can do that.

thanku