Q. 31

Expert-verified
Found in: Page 791

### Physics for Scientists and Engineers: A Strategic Approach with Modern Physics

Book edition 4th
Author(s) Randall D. Knight
Pages 1240 pages
ISBN 9780133942651

# In FIGURE EX28.31, what is the value of the potential at points ?

The potential at points are

See the step by step solution

## Step 1 : Given information and formula used

Given :

Theory used :

Kirchhoff's loop rule states that the sum of all the electric potential differences around a loop is zero. It is also sometimes called Kirchhoff's voltage law or Kirchhoff's second law.

## Step 2 : Finding the value of current

The ground wire has no effect on the circuit's behavior, but it does provide a location on the circuit with zero potential, which is the same as the potential of the earth.

As a result, the potential zero is at point 'c'.

Assume we proceed around a loop, measuring potential differences among circuit parts along the way, and when we get back to the starting point, the algebraic sum of these differences is zero.

Let's create a clockwise loop and apply equation (28.2) to it, with the voltage across the resistors being negative because the current is flowing in the same direction.

The emf is positive because the current flows from the negative to the positive terminal in the battery, whereas the emf is negative because the current flows from the positive to the negative terminal.

Put the values to get :

## Step 3 : Finding value of the potential at points

The current is positive, indicating that it is moving in a clockwise direction. Because the current should move from the greater potential to the lower potential while moving clockwise, it passes through point 'c' before point 'a', resulting in a negative differential between the two places.

We may get by putting the value of

To calculate the voltage across the resistance, we use Ohm's law.

Because the current goes from the greater potential to the lower potential when it passes through point 'b' before point 'c', the difference between the two points is positive.

By plugging in the value of by zero :