Chapter 23, Problem 84A

To determine

To explain: The change of current in the second $60\Omega$ resistor of both the circuits for the given change.

Answer to Problem 84A

The current in second $60\Omega$ resistor of a circuit A is zero.The current in second $60\Omega$ resistor of a circuit B remains constant.

Explanation of Solution

Introduction:

When the voltmeter is connected across a component in a circuit, then the voltmeter is

said to be connected in parallel connection. The potential difference across both the

voltmeter and the electrical element are equal.

When the voltmeter is connected along the component in the circuit, then the voltmeter is

said to be connected in series connection. The current flowing through both the voltmeter

and the electrical element are equal.

Calculation:

Consider Circuit A, three resistor of $60\Omega$ each are connected in series connection.

In series connection, the current flowing through each of the resistor is same.

When one of the resistors in the series connection is removed, the current flowing in the whole circuit gets cut off.

That is, when the switch of the first $60\Omega$ resistor is open for the first time, there will not be any current flow in the remaining two resistors of $60\Omega$ .

Hence, the second $60\Omega$ resistor of a circuit A is zero.

Consider Circuit B, three resistor of $60\Omega$ each are connected in parallel connection.

In parallel connection, the current flowing through each of the resistor is constant.

When one of the resistors in the parallel connection is removed, the current flowing in the circuit remains constant.

That is, when the switch of the first $60\Omega$ resistor is open for the first time, there will not be any change in the current flow in the remaining two resistors of $60\Omega$ .

Hence, the second $60\Omega$ resistor of a circuit B is remains constant.

Conclusion:

Thus, the current in the second $60\Omega$ resistor of a circuit A is zero and the current in the second $60\Omega$ resistor of a circuit B remains constant.