NEET Physics: Physics - Electricity questions with solutions

Q1. The electrical energy in kilowatt hours consumed in operating ten \( 50 ~ W \) bulbs for 10 hrs/day in a month of 30 days is

1. 1500
2. 15000
3. 15
4. 150

Answer: 150

Ten 50 W bulbs draw a total of 500 W, which is 0.5 kW. Running for 10 hours per day over 30 days gives 300 hours, so the energy used is 0.5 × 300 = 150 kWh.

Q2. Assertion A galvanometer can be used as a voltmeter to measure the voltage across a given section of the circuit. Reason For this it must be connected in parallel with that section of the circuit.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Answer: Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

A galvanometer can be converted into a voltmeter by adding a large resistance, allowing it to measure potential difference. A voltmeter is connected in parallel so it measures the voltage across the same two points as the section of the circuit, which is exactly why the assertion is true.