MCQ Questions for Class 10 Science Chapter 12 Electricity
1. What is the amount of current flowing through an electric press, if the amount of charge passing through a conductor in 10 minutes is 300 C?
(a) 30 A
(b) 0.3 A
(c) 0.5 A
(d) 5 A
Answer(c) 0.5 A
2. When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:
3. A wire of length ℓ, made of material resistivity ρ is cut into two equal parts. The resistivity of the two parts are equal to,
(c) 2 ρ
(d) 4 ρ
Answer(a) Resistivity of the material depends only on the nature of material not dimensions.
4. The temperature of a conductor is increased. The graph best showing the variation of its resistance is
Answer(a) Resistance is directly proportional to temperature of the conductor.
5. An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:
(a) 0.92 A
(b) 2.9 A
(c) 9.2 A
(d) 92 A
Answer(c) 9.2 A
6. Keeping the potential difference constant, the resistance of the circuit is halved. The current will become:
(b) Four times
7. 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 × 103 joule
(b) 2 × 105 joule
(c) 2 × 104 joule
(d) 2 × 102 joule
Answer(b) W= qV= 20000 × 10 = 2,00, 000 = 2 × 105 J
8. The resistance whose V-I graph is given below is
Answer(b) Resistance = slope line of V-I graph =
9. To get 2 Ω resistance using only 6 Ω resistors, the number of them required is
Answer(b) Three resistors of 2 Ω is required to get 6 Ω because resultant is more than individual so they all must be connected in series.
10. If in the given arrangement, the three resistors are to be replaced by a single resistor. What will be the value of this resistor?
Answer(c) 9 Ω
11. 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
(d) None of these
Answer(b) In parallel combination, voltage remains same across two points.
12 Two appliances of rating 200 watt-250 volts and 100 watt-250 volts are joined in series to a 250 volts supply. Total power consumed in the circuit is
(a) 46 watt
(b) 67 watt
(c) 10 watt
(d) 30 watt
Answer(b) 67 watt
13. Two wires of same length and area made of two materials of resistivity ρ1 and ρ2 are connected in series to a source of potential V. The equivalent resistivity for the same area is
Answer(c) For same length and area of cross-section R ∝ p. For series combination, equivalent resistance is
Rs = R1 + R2
⇒ Ps = ρ1 + ρ2
14. The least resistance obtained by using 2 Ω, 4 Ω, 1 Ω and 100 Ω is
a) < 100 Ω (b) < 4 Ω
(c) < 1 Ω (d) > 2 Ω
Answer(c) In parallel combination, the equivalent resistance is smaller than the least resistance used in the circuit.
15. A wire of resistance R1 is cut into five equal pieces. These five pieces of wire are then connected in parallel. If the resultant resistance of this combination be R2, then the ratio R1/ R2 is:
16. 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) In series, Rs = R1 + R2 = 10 Ω
17. Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them is in the ratio.
18. If R1 and R2 be the resistance of the filament of 40 W and 60 W respectively operating 220 V, then
(a) R1 < R2
(b) R2 < R1
(c) R1 = R2
(d) R1 ≥ R2
Answer(b) Using power, P = V2/R or R = V2/P
For the same voltage, R ∝ 1/P
More the power, lesser the resistance.
Accordingly, R2 < R1
19. A coil in the heater consume power P on passing current. If it is cut into halves and joined in parallel, it will consume power
20. 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