Question

in a circuit shown in figure, the heat produced in 3
ohm resistor due to a current flowing in it is 12 J.
The heat produced in 4 ohm resistor is
(1) 2J
(3) 64 J

(2) 4 J
(4) 32J​

Answer 1

Answer:

Please go through the image attached

Hope this helps

Answer 2

Answer:

The heat produced in 4 ohm resistor is 4 J.

(2) is correct option.

Explanation:

Given that,

Heat produced in 3 ohm = 12 J

We need to calculate the heat produced in 3 ohm

Using formula of heat

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

Put the value into the formula

$12=\dfrac{V^2}{3}\times t$.....(I)

We need to calculate the voltage across 4 ohm

Using formula of voltage

$V'=V\times\dfrac{R_{2}}{R_{1}+R_{2}}$

Put the value into the formula

$V'=V\times\dfrac{4}{6}$

We need to calculate the heat produced in 3 ohm

Using formula of heat

$H=\dfrac{(V\times\dfrac{4}{6})^2}{4}\times t$....(II)

Now, divided equation (II) by equation (I)

$\dfrac{H}{12}=\dfrac{\dfrac{(V\times\dfrac{4}{6})^2}{4}\times t}{\dfrac{V^2}{3}\times t}$

$\dfrac{H}{12}=\dfrac{V^2\times16}{4\times36}\times t\times\dfrac{3}{V^2\times t}$

$\dfrac{H}{12}=\dfrac{1}{3}$

$H=4\ J$

Hence, The heat produced in 4 ohm resistor is 4 J.