## Chapter 12: Electricity

Q1. The temperature of a conductor is increased. The graph best showing the variation of its resistance is

Answer: a

Q2. A battery of 10 volt carries 20,000 C of charge through a resistance of 20 Ω. The work done in 10 seconds is

(a) 2 × 10_{3} joule

(b) 2 × 10^{5}joule

(c) 2 × 10^{4} joule

(d) 2 × 10^{2} joule

Answer: b

Q3. A boy records that 4000 joule of work is required to transfer 10 coulomb of charge between two points of a resistor of 50 Ω. The current passing through it is

(a) 2 A

(b) 4 A

(c) 8 A

(d) 16 A

Answer: c

Q4. The resistance whose V-I graph is given below is

Answer: b

Q5. To get 2 Ω resistance using only 6 Ω resistors, the number of them required is

(a) 2

(b) 3

(c) 4

(d) 6

Answer: b

Q6. Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is

(a) current

(b) voltage

(c) resistance

(d) None of these

Answer: b

Q7. Calculate the current flows through the 10 Ω resistor in the following circuit.

(a) 1.2 A

(b) 0.6 A

(c) 0.2 A

(d) 2.0 A

Answer: b

Q8. Two resistors are connected in series gives an equivalent resistance of 10 Ω. When connected in parallel, gives 2.4 Ω. Then the individual resistance are

(a) each of 5 Ω

(b) 6 Ω and 4 Ω

(c) 7 Ω and 4 Ω

(d) 8 Ω and 2 Ω

Answer: b

Q9. If P and V are the power and potential of the device, the power consumed with a supply potential V_{1} is

Answer: c

Q10. A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of

(a) more length

(b) less radius

(c) less length

(d) more radius

Answer: d