Question

a coil in the heater consume power P on passing current if it is cut into half and joined in parallel it will consume power​

Answer 1

Explanation:

If the rod is divided into two equal parts, then each part of the rod will have a resistance of R/2. Now these two parts of the rod are connected in parallel and a voltage V is applied across them. Hence the total power consumed is P = V2/R is the power consumed by the original rod when voltage V is applied across it.

Answer 2

Given:

The power consumed by the coil of a heater is equal to $P$.

To Find:

What will be the power consumed by it if it is cut into two halves and connected in parallel.

Solution:

Let the voltage across which the coil is connected is equal to $V$.

We know that the power consumed by a resistance $R$ connected between a voltage $V$ is equal to $\frac{V^2}{R}$ .

So, $P=\frac{V^2}{R}$

When the coil is cut into halves, the resistance of each half = $\frac{R}{2}$

Equivalent resistance when they are connected in parallel $=\frac{(R/2)*(R/2)}{(R/2)+(R/2)}$

                                                                                                  $=\frac{R}{4}$

Power consumed by this new arrangement, $P'=\frac{V^2}{(R/4)}$

                                                                              $=4\frac{V^2}{R}$

                                                                              $=4P$

Hence, when the coil is cut into two halves and connected in parallel, the new power consumed by it will be 4 times the power consumed initially.

#SPJ3