CBSE Class 10 Physics Electricity MCQs Set D

Question: A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross section of the filament in 16 seconds would be roughly
a) 10²⁰
b) 10¹⁶
c) 10¹⁸
d) 10²³
Answer: a

Question: One coulomb charge is equivalent to the charge contained in:
a) 2.6 × 10¹⁹ electrons
b) 6.2 × 10¹⁹ electrons
c) 2.65 × 10¹⁸ electrons
d) 6.25 × 10¹⁸ electrons
Answer: d

Question: The image shows a combination of 4 resistors. What is the net resistance between the two points in the circuit?
a) 0.5 Ω
b) 1.0 Ω
c) 1.5 Ω
d) 2.0 Ω
Answer: b

Question: The unit for measuring potential difference is:
a) watt
b) ohm
c) volt
d) kWh
Answer: c

Question: The p.d. across a 3Ω resistor is 6 V. The current flowing in the resistor will be:
a) 1/2 A
b) 1 A
c) 2 A
d) 6 A
Answer: c

Question: Which of the following represents voltage?
a) Work done / Current × Time
b) Work done × Charge
c) Work done × Time / Current
d) Work done × Charge × Time
Answer: a

Question: Which of the following is the most likely temperature of the filament of an electric light bulb when it is working on the normal 220 V supply line?
a) 500°C
b) 1500°C
c) 2500°C
d) 4500°C
Answer: c

Question: 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

Question: If the current flowing through a fixed resistor is halved, the heat produced in it will become:
a) double
b) one-half
c) one-fourth
d) four times
Answer: c

Question: Two bulbs are rated 40W, 220W and 60W, 220W. The ratio of their resistances will be:
a) 4:3
b) 3:4
c) 2:3
d) 3:2
Answer: d

Question: The work done in moving a unit charge across two points in an electric circuit is a measure of:
a) current
b) potential difference
c) resistance
d) power
Answer: b

Question: Which of the following units could be used to measure electric charge?
a) ampere
b) joule
c) volt
d) coulomb
Answer: d

Question: Which one among a bar of an alloy of mass 2 kg and a 3 kg iron bar of same dimension has greater resistivity?
a) Iron bar because it has higher mass.
b) Alloy bar because it has lower mass.
c) Iron bar because it has the same types of atoms.
d) Alloy bar because it has different types of atoms.
Answer: d

Question: In order to reduce electricity consumption at home, what kind of appliance should one purchase?
a) one which draws low power
b) one which produces less heat
c) one which operates at a higher voltage
d) one which draws a high amount of current
Answer: c

Question: Which combination of a 2 Ω resistor and 4 Ω resistor offers the least resistance to current in the circuit?
a) Series combination, which results in a net resistance of 2 Ω.
b) Parallel combination, which results in a net resistance of 2 Ω.
c) Series combination, which results in a net resistance of 1.5 Ω.
d) Parallel combination, which results in a net resistance of 0.5 Ω.
Answer: d

Question: In an electrical circuit two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be:
a) 5 J
b) 10 J
c) 20 J
d) 30 J
Answer: c

Question: How much more heat is produced, if the current is doubled?
a) twice the original amount
b) thrice the original amount
c) four times the original amount
d) five times the original amount
Answer: c

Question: The device used for measuring potential difference is known as:
a) potentiometer
b) ammeter
c) galvanometer
d) voltmeter
Answer: d

Question: A cooler of 1500 W, 200 volt and a fan of 500 W, 200 volt are to be used from a household supply. The rating of fuse to be used is:
a) 2.5 A
b) 5.0 A
c) 7.5 A
d) 10 A
Answer: a

Question: If n resistors each of resistance R are connected in parallel combination then their equivalent resistance is:
a) R/n²
b) n²/R
c) n/R
d) R/n
Answer: c

Question: The heating element of an electric heater should be made with a material, which should have
a) high specific resistance and high melting point
b) high specific resistance and low melting point
c) low specific resistance and low melting point
d) low specific resistance and high melting point
Answer: a

Question: Two resistors connected in series gives an equivalent resistance of 10 Ω. When connected in parallel, give 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: d

Question: A current I passes through a wire of length l, radius r and resistivity ρ. The rate of heat generated is
a) I²ρl/r
b) I²ρl/πr²
c) I²ρl/πr
d) none of these
Answer: b

Question: A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is:
a) 0.5 Ω
b) 6 Ω
c) 12 Ω
d) 24 Ω
Answer: d

Question: Ohm’s law gives a relationship between:
a) current and resistance
b) resistance and potential difference
c) potential difference and electric charge
d) current and potential difference
Answer: d

Question: The unit of electric power may also be expressed as
a) volt ampere
b) kilowatt hour
c) watt second
d) joule second
Answer: b

Question: Resistance of conductor is doubled keeping the potential difference across it constant. The rate of generation of heat will
a) become one fourth
b) be halved
c) be doubled
d) become four times
Answer: b

Question: When a 4 Ω resistor is connected across the terminals of a 12 V battery, the number of coulombs passing through the resistor per second is:
a) 0.3
b) 3
c) 4
d) 12
Answer: b

Question: 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

Question: If a wire of resistance 1Ω is stretched to double its length, then resistance will be
a) 1/2 Ω
b) 2 Ω
c) 14 Ω
d) 4 Ω
Answer: d

Question: What is the relationship between resistance and current?
a) They are directly related to each other.
b) They are inversely related to each other.
c) The resistance has a greater magnitude than current.
d) The current has a greater magnitude than resistance.
Answer: b

Question: By what other name is the unit joule/coulomb called ?
Answer: Volt

Question: How much work is done when one coulomb charge moves against a potential difference of 1 volt ?
Answer: 1 J

Question: a volt is a joule per coulomb.
Answer: (b)

(a) Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.
(b) The Assertion and the Reason are correct but the Reason is not the correct explanation of the Assertion.
(c) Assertion is true but the Reason is false.
(d) The statement of the Assertion is false but the Reason is true.

Question:
Assertion: Conductors allow the current to flow through themselves.
Reason: They have free charge carriers.
Answer: a

Question:
Assertion: Bending of wire decrease the resistance of electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
Answer: a

Question:
Assertion: In an open circuit, the current passes from one terminal of the electric cell to another.
Reason: Generally, the metal disc of a cell acts as a positive terminal.
Answer: d

Question:
Assertion: When a battery is short circuited, the terminal voltage is zero.
Reason: In short circuit, the current is zero.
Answer: c

Question:
Assertion: The statement of Ohm’s law is K = IR
Reason: V = IR is the equation which defines resistance.
Answer: c

Question: Connecting many resistors in parallel, will ____________ the resistance of the circuit.
Answer: Equivalent resistance in parallel combination will be smaller than the lest resistance used in circuit.

Question:746 watts make ____________ horse power.
Answer: One

Question: Two resistors are in parallel when they have ____________ common points.
Answer: One

Question: Current is a ____________ quantity.
Answer: Current is a scalar quantity as it has no particular direction of flow.

Question: Presence of argon prolongs the life of ____________ .
Answer: Filament of electric bulb

Question: Work done on unit charge is called as ____________ .
Answer: Potential difference