Question

Express the heat produced in calories, when I amperes are passed for t secounds through a resistor having the resistance of R ohms

Answer 1

Answer:

V = I R

and energy expended,

W = V It = IR*I*t = I2 R t joules

Explanation:

$W = V \times \dfrac{V}{R}t = \dfrac{V^2}{R}t joules$

Answer 2

Answer:

H = I^2Rt/ 4.184 cal

Explanation:

From Joule's law of heating,

H = I^2Rt. _(1)

where, H is the heat produced when a current of ampere I is passed for t seconds through a resistor of resistance R.

The heat generated in a conductor due to the flow of electric current is also expressed in calories (cal).

We have,. I cal= 4.184 J

or,. 1 J =1/ 4.184 cal

substituting the value in equation (1) ,

H = I^2 Rt ×1/ 4.184 cal

=I^2 Rt / 4.184 cal

Hence, I^2Rt ×4.184 cal of heat is produced

when I ampere is passed for t sec. through a resistor of resistance R.