Question

3.While performing an experiment to study the dependence of current on the potential difference across two ends of the resistor, a student keeps the circuit closed for a long time to measure the current and potential difference. State how the resistance of the resistor will be affected?

Answer 1

Answer:

While performing the experiment "to study the dependence of current flowing through a resistor on the potential difference across its ends" if a student keeps the circuit 'ON' for a long time to measure the current and voltage, the (A) 1 ammeters zero erro

(B) potential difference of the cell will change

(C) voltmeter will start giving wrong readings

(D) resistor will get heated upto change in the values of its resistance✔✔✔✔✔

Answer 2

Answer:-

This will result in increase in the resistance of the resistor.

Explanation:-

• The student had kept the circuit closed for long time this will increase the amount of heat in circuit because we know that by Joule's Heating Law time is directly proportional to the heat in an electric circuit.

• Increase in heat in the circuit will result in Increase in the resistance of the resistor as by Joule's heating law Heat is directly proportional to the resistance.

• Therefore the resistance of the resistor will increase if the student keep the circuit closed for a long time.

• Because of increase in heat the volt meter will also start to give wrong readings.

• The Ammeter will also stop working properly.

Joule's Heating Law:-

• It states that heat is directly proportional to the square of current in the circuit.

• Heat is directly proportional to the resistance in the circuit.

• Heat is directly proportional to the time at which the current is passed through the circuit.