Class 10 Electricity Important Questions

Important Questions Previous Years Questions Notes

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.
    

Solutions

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