(A) What do you understand by the term potential difference” ?(B) What is meant by saying that the potential difference between two points is 1volt ?(C) What is the potential difference between the terminals of the battery if 250joules of work is required to transfer 20coulombs of charge from one terminal of the battery to the other?(D) What is a voltmeter? How is a voltmeter connected in the circuit to measure the potential difference between two points. Explain with the help of a diagram.(E) State whether a voltmeter has a high resistance or a low resistance. Give reason for your answer

(A) Potential Difference: The term "potential difference" refers to the difference in electric potential energy per unit charge between two points in an electric field. It is the work done to move a positive test charge from one point to another, divided by the magnitude of the charge. It is measured in volts (V).

(B) Meaning of 1 Volt: When we say that the potential difference between two points is 1 volt, it means that 1 joule of work is done to move 1 coulomb of charge between the two points. In simpler terms, if you have 1 volt between two points, transferring 1 coulomb of charge from one point to another will require 1 joule of work.

(C) Potential Difference Calculation: The formula to calculate the potential difference (V) is:

V = W/Q

Where:

W is the work done (in joules)
Q is the charge (in coulombs)
Given:

W = 250 joules
Q = 20 coulombs
Substitute the values into the formula:

V = 250 joules / 20 coulombs = 12.5 volts

So, the potential difference between the terminals of the battery is 12.5 volts.

(D) Voltmeter and Its Connection: A voltmeter is an instrument used to measure the potential difference between two points in a circuit. It is connected in parallel with the component or section of the circuit where the potential difference is to be measured.

Diagram: [ + ]——(Voltmeter)——[ - ]
(Power source or component to measure voltage)

The voltmeter is connected across the two points, ensuring that the current does not flow through it directly but instead measures the difference in electric potential between the points.

(E) Resistance of a Voltmeter: A voltmeter has a high resistance. This is because it is designed to measure the potential difference without drawing any significant current from the circuit. If a voltmeter had low resistance, it would allow current to flow through it, which would affect the measurement of the potential difference. Therefore, a high resistance ensures that the voltmeter does not alter the current in the circuit while measuring the potential difference.