CBSE Class 10 Physics Electricity MCQs Set B

Question. What is immaterial for an electric fuse wire? 
(a) Its specific resistance
(b) Its radius
(c) Its length
(d) Current flowing through it
Answer : C

Question. The resistivity does not change if 
(a) the material is changed
(b) the temperature is changed
(c) the shape of the resistor is changed
(d) both material and temperature are changed.
Answer : C

Question. Choices for the correct combination of elements from column-I and column-II are given as options (a), (b), (c) and (d) out of which one is correct? 
Column-I Column-II
(P) Current             1. ohm
(Q) Potential          2. ampere
(R) Resistance       3. ohm m
(S) Resistivity 4. volt
(a) P-2, Q-4, R-1, S-3
(b) P-3, Q-4, R-2, S-1
(c) P-4, Q-3, R-1, S-2
(d) P-2, Q-1, R-4, S-3
Answer : A

Question. A 100 W bulb B₁, two 60 W bulbs B₂ and B₃ are connected to a 250 V source as shown. If W₁, W₂ and W₃ are powers of the bulbs, then 

(a) W₁ > W₂ = W₃
(b) W₁ > W₂ > W₃
(c) W₁ < W₂ = W₃
(d) W₁ < W₂ < W₃.
Answer : D

Question. The resistivity of a wire depends on
(a) Length, material and area of cross section
(b) Area of cross section
(c) Length
(d) Material
Answer : A

Question. For which of the following substances, resistance decreases with temperature
(a) Carbon
(b) Mercury
(c) Platinum
(d) Copper
Answer : A

Question. Four cells each of e.m.f E are joined in parallel to form a battery. The equivalent e.m.f of the battery will be
(a) E
(b) 4 E
(c) E / 4
(d) E = 0
Answer :A

Question. A cylindrical conductor of length l and uniform area of cross section A has resistance R.
Another conductor of length 2l and resistance R of the same material has area of cross- section:
(a) A /2
(b) 3A /2
(c) 2A
(d) 3A
Answer : C

Question. Two electric bulbs have resistances in the ratio 1:2. If they are joined in series, the energy consumed in them are in the ratio
(a) 0.0840277777777778
(b) 0.0430555555555556
(c) 0.167361111111111
(d) 0.0423611111111111
Answer : A

Question. Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the Ω0 W bulb will be:
(a) 0.4 A
(b) 0.6 A
(c) 0.8 A
(d) 1 A
Answer : D

Fill in The Blank

True/False

Question. One kilowatt is equal to 10 horse power.
Answer : False

Question. The temperature coefficient of resistance of a wire is 0.00125/cC. The resistance of the wire is 1 ohm at 300 K. The resistance will be 2 ohm at 1100 K.
Answer : False

Question. When two resistances 1 W and 3 W are connected in parallel, their equivalent resistance is less than 1 W .
Answer : True

Question. The commercial unit of electrical energy is kilowatthour (kWh).
Answer : True

Question. The quantity of charge flowing past a point multiplied by time is a current.
Answer : False

Question. The sun looks red at sunset because most of the blue light in sun rays is scattered leaving behind red yellow lights.
Answer : False

Matching Questions

Question. Match the Following

Answer : A-q, B-r, C-p, D-s

Question. 

Answer : (a) A-q, s, B-p, C-q, s D-r

Question. 

Answer : (a) A-p, B-p, C-s, q, D-r

Question. 

Answer : (b) A-p, B-q, r, C-q, D-s

Answer : (a) A-q, B-r, C-p, s, D-s

Answer : (a) A-r, B-q, C-p, D-t

Question. 

Answer : 1-(c), 2-(d), 3-(a), 4-(b)

Assertion & Reasoning Based MCQs

(a) Both assertion and reason are true, and reason is correct explanation of the assertion.
(b) Both assertion and reason are true, but reason is not the correct explanation of the assertion.
(c) Assertion is true, but reason is false.
(d) Assertion is false, but reason is true.

Question. Assertion : A current carrying wire should be charged. 
Reason : The current in a wire is due to flow of free electrons in a definite direction.
Answer : D

Question. Assertion : A voltmeter and ammeter can be used together to measure resistance and power. 
Reason : Power and resistance can be calculated from voltage and current.
Answer : A

Question. Assertion : The connecting wires are made of copper. 
Reason : The electrical conductivity of copper is high.
Answer : A

Question. Assertion : If 10 bulbs are connected in series and one bulb fused, then the remaining 9 bulbs will not work. 
Reason : Bulb of higher wattage will give less bright light.
Answer : B

Question. Assertion : The 200 W bulbs glows with more brightness than 100 W bulbs. 
Reason : A 100 watt bulb has more resistance than a 200 W bulb.
Answer : A

Question. Assertion : A bird perches on a high power line and nothing happens to the bird. 
Reason : The circuit is incomplete for the bird sitting on high power line.
Answer : A

Question. Assertion : It is advantageous to transmit electric power at high voltage. 
Reason : High voltage implies high current.
Answer : C

Question. Assertion : Electrons always move from a region of lower potential to a region of higher potential. 
Reason : Electron has a negative charge.
Answer : A

Question. Assertion : Good conductors of heat are also good conductors of electricity and vice versa. 
Reason : Mainly electrons are responsible for conduction.
Answer : A

Question. Assertion : The coil of a heater is cut into two equal halves and only one of them is used into heater. The heater will now require half the time to produce the same amount of heat. 
Reason : The heat produced is directly proportional to square of current.
Answer : B