Question

Derive the expression of
series and
Parallel combination.
and write The Heating
effect of Electric current​

Answer 1

Answer:

Derive the expression of

series and

Parallel combination.

and write The Heating

effect of Electric current(a) When an electric charge Q moves against a p.d. V, the amount of work done is given by

W=Q×V                           ---------------(1) 

We know,  current , I=tQ

Q=I×t                                ------------(2)

By ohm's law , IV=R

V=I×R                             --------------(3)

Putting eqs. (2) and (3) in eq. (1),

W=I×t×I×R

W=I2Rt

Assuming that all the electrical work done is converted into heat energy , we get

Heat produced , H=I2Rtjoules

This relation is known as Joule's law of heating.

(b) Given : P=12W,V=12V,t=60sec

using the equation of power

P=VI

I=P/V=12/12=1A

The Ohm's law states that

V=IR

R=V/I=12/1=12ohm

The formula for heat is:

H=I2Rt

H=12×12×60

H=720J