Question

The reading on a high resistance voltmeter, when a cell is connected across it, is 2.2 V. When the terminals of the cell are also connected to a resistance of 5$\Omega$ as shown in the circuit, the voltmeter reading drops to 1.8 V. Find the internal resistance of the cell.

Answer 1

Answer:

1.1 ohm is the correct answer.

Explanation:

Resistance is the property of material to resist or oppose the flow of current through it.

Voltmeter is the device used to measure potential difference.

It gives the value in volts.

Internal resistance is the resistance which limits the voltage or potential difference that can be given to the external load.

Given data:

A reading is taken on a high resistance voltmeter, when a cell is connected across it.

Voltmeter reading = 2.2 V = E

When the terminals of the cell are also connected to a resistance.

Resistance = R = 5ohm

Voltage drop = 1.8 V = V

To Find:

the internal resistance of the cell =? = r

We know that internal resistance r is given by the formula,

r = ((E/V) - 1) * R

= ((2.2/1.8)-1) * 5

=(1.22-1) *5

= 0.22*5

=1.11 ohm

Internal resistance is found out to be 1.1 ohm

Hence,

1.1 ohm is the correct answer.

Answer 2

Hello mate, Here is your Answer

Given :-

A reading is taken on a high resistance voltmeter, so when a cell is connected across it.

Voltmeter reading = 2.2 V = E

When the terminals of the cell are also connected to a resistance.

Resistance = R = 5ohm

Voltage drop = 1.8 V = V

We Have to Find:

the internal resistance of the cell =? = r

We know that internal resistance r is given by the formula,

r = ((E/V) - 1) * R

= ((2.2/1.8)-1) * 5

=(1.22-1) *5

= 0.22*5

=1.11 ohm

So,

1.1 ohm is the correct answer.