# Class 10 Electricity Important Questions

Electricity Important Questions

1. The potential difference between the terminals of an electric heater is 60 V when it draws a current of 4 A from the source. What current will the heater draw if the potential difference is increased to 120 V.
2. The V-I graph of three resistors is shown below. Which resistor has maximum resistance? 3. An electric iron is marked 400 W and 220 V. What is the resistance when iron is hot? How long could it be used for ₹3 of electrical energy that costs 15 paise per unit.
4. A 20 cm long uniform wire of resistance 5 Ω is stretched to a uniform wire of 40 cm length. What will be the resistance of new wire?
5. If R1 and R2 are the resistances of filaments of a 400 W and a 200 W lamp, designed to operate on the same voltage, then find the relationship between R1 and R2.
6. .
1. State Ohm’s law and write its expression.
2. Draw a circuit diagram to verify Ohm’s law.
7. The rating of bulb B1 is 60 V, 12 W & bulb B2 is 100 V, 100 W. Find the maximum emf of the battery so that all bulbs remain safe. 8. Find equivalent resistance between P and Q: 9. Find equivalent resistance: 10. In reference to the given figure, find the current flowing through 20 Ω resistor. 