Electricity Class 10 imp. questions

Electricity Class 10 imp. questions (part 1)

1. An electric heater is salted at 1500w. How much heat is produced per hour?
2. A student says that the resistance of two wires of same length and same area of cross section is same. This statement is correct if (a) Both wires are of different materials (b) Both wires are made of same material and are at different temperature. (c) Both wires are made of same material and are at same temperature. (d) Both wires are made of different materials and are at the same temperature.
3. Alloys are used in electrical heating devices rather than pure metals. Give reason.
4. On what factor does the resistance of a conductor depend?
5. Calculate the number of electron consisting one coulomb of charge?
6. Apiece of wire of resistance 20Ω is drawn out so that its length is increased to twice its original length calculate the resistance of the wire is the new situation?
7. A battery made of 5cells each of 2Vand have internal resistance 0.1, 0.2, 0.3, 0.4, and 0.5 Ω is connected across 10Ω resistance. Draw circuit diagram and calculate the current flowing through 10 resistances?
8. You have two circuits (i) a 6V battery is series with 1 and 2 resistor Ω  (ii)  a 4V battery in parallel with 12 and 2 resistors. Ω Ω Compare the power used in 2Ω resistor in each case. 
9. (a) Define electrical energy with S.I. unit? (b) A household uses the following electric appliance; (i) Refrigerator of rating 400w for ten hour each day. (ii)  Two electric fans of rating 80w each for twelve hours each day. (iii) Six electric tubes of rating 18w each for 6hours each day.
10. Calculate the electricity bill of the household for the month of June if the cost per unit of electric energy is Rs. 3.00. For the circuit arrangement shown below, a student would observe.                                             (a)  Some reading in both ammeter and voltmeter. (b) No reading in either the ammeter or the voltmeter. (c)  Some reading in the ammeter but no reading in the voltmeter. (d)  Some reading in the voltmeter but no reading in the ammeter.