Well structured WBBSE Class 10 Physical Science MCQ Questions Chapter 6 Current Electricity can serve as a valuable review tool before exams.
Current Electricity Class 10 WBBSE MCQ Questions
Multiple Choice Questions :
Question 1.
The SI unit of electric charge is:
(A) Coulomb
(B) Ampere
(C) Ohm
Answer:
((A) Coulomb
Question 2.
The unit of potential difference is :
(A) joule
(B) volt
(C) ohm
(E) ampere
Answer:
(B) volt
Question 3.
The unit of electrical power is:
(A) volt
(B) watt
(C) ohm
(D) joule
Answer:
(B) wait
Question 4.
What material an electric fuse made of?
(A) copper
(B) silver
(C) iron
(D) tin-lead alloy
Answer:
(D) Tintead alloy
Question 5.
Unit of resistance is:
(A) ampere
(B) ohm
(C) coulomb
(D) joule
Answer:
(B) ohm
Question 6.
Specific resistance of a conductor dipends on :
(A) its length
(B) its cross-sectional area
(C) its material
Answer:
(C) its nateriat
Question 7.
The amount of heat developed due to current can be known from:
(A) Ampere’s law
(B) Ohm’s law
(C) Joules law
Answer:
(C) Joules lau
Question 8.
The example of conservation of electrical energy into mechanical energy is:
(A) electric cell
(B) electric motor
(C) electric lamp
Answer:
(B) electric motor
Question 9.
The action of electric current on magnet was first observed by:
(A) Oerested
(B) Joule
(C) Barlow
(D) Newton
Answer:
(A) Oerested
Question 10.
Ohm’s law is related to:
(A) current and potential difference
(B) volume and pressure
(C) temperature density.
Answer:
(A) current and potenitial difference
Question 11.
Electric supply company measures the electricity consumed by the consumers in their household in terms of :
(A) joule unit
(B) watt-hour
(C) B.O.T. units
Answer:
(C) B.OT inits
Question 12.
Which one is not conductor of electricity:
(A) copper
(B) gold
(C) aluminium
(D) plastic
Answer:
(D) plastic
Question 13.
Ammeter measures:
(A) resistance
(B) potential difference
(C) current
Answer:
(C) current
Question 14.
Potential difference is measured by:
(A) Voltmeter
(B) Volameter
(C) Galvanometer
Answer:
(A) Voltmeter
Question 15.
If the length of the conductor is kept unaltered and cross section of conductor is increased then its resistance:
(A) increases
(B) decreases
(C) remains unaltered
Answer:
(B) decreases
Question 16.
If the corss section of the conductor is kept unaltered and length of conductor is increased then its resistance:
(A) increases
(B) decreases
(C) remains unaltered
Answer:
(A) increases
Question 17.
The correct relation is :
(A) Watt = \(\frac{\text { Volt }}{\text { Ampere }}\)
(B) Watt = \(\frac{\text { Ampere }}{\text { Volt }}\)
(C) Watt = Volt × Ampere
Answer:
(C) Watt = Volt × Ampere
Question 18.
The physical quantity measured by kilowatt-hour
(A) Electric power
(B) Electric energy
(C) Current
Answer:
(B) Electric energy
Question 19.
What is the equivalent resistance of the resistances 2 ohm, 3 ohm and 5 ohm combined in parallel ?
(A) 10 ohm
(B) \(\frac{30}{31}\) ohm
(C) \(\frac{31}{30}\) ohm
(D) 20 ohm
Answer:
(B) \(\frac{30}{31}\) ohm
Question 20.
What is the equivalnnt resistance of the resistances 3 ohm, 5 ohm and 12 ohm combined in series?
(A) 15 ohm
(B) 18 ohm
(C) 20 ohm
(D) 30 ohm
Answer:
(C) 20 ohm
Question 21.
Force between two charges separated by a certain distance in air is F. If each charge was doubled and distance between them also doubled, then force would be
(A) F
(B) 2 F
(C) 4 F
(D) F / 4
Answer:
(A) F
Question 22.
What is the dimensional formula of electric charge ?
(A) [M0 L0 TA]
(B) [M0 L0 T-1 A]
(C) [M0 L0 TA-1]
(D) [M0 L0 T-1 A-1]
Answer:
(A) [M0 L0 TA]
Question 23.
A charge q1 exerts some force on a second charge q2. If a hird charge q3 be brought near, the force of q1 exerted on q2.
(A) decreases
(B) increases
(C) remains unchanged
(D) increases if q3 is of same sign as q}1 and decreases of q3 is of opposite sign.
Answer:
The force between q1 and q2 is not affected by q3.
Question 24.
The dimensional formula of electric density is
(A) MLT-2 A-1
(B) MLT-3 A-1
(C) ML2 T-3 A-1
(D) ML2 T-3 A-2
Answer:
(A) MLT-3 A-1
Question 25.
Electric flux at a point in an electric field is:
(A) positive
(B) negative
(C) zero
(D) none of these
Answer:
(C) zero
Question 26.
A soap bubble is charged to a potential of 16 V. Its radius is the doubled. The potential of the bubble now will be :
(A) 16 V
(B) 8 V
(C) 4 V
(D) 2 V
Answer:
(B) 8 V
Question 27.
A resistor of 0.5 Ω is connected to another resistor is parallel combination to get an equivalent resistance of 0.1 Ω. The resistance of second resistor is :
(A) 1/8 Ω
(B) 0.2 Ω
(C) 0.6 Ω
(D) 8 Ω
Answer:
(A) 1/8Ω
Question 28.
If six identical cells are each having emf of 6 V are connected in parallel the emf of the combination is :
(A) 1 V
(B) 1 / 6V
(C) 6 V
(D) 36 V
Answer:
(C) 6 V
Question 29.
The resistance of discharge tube is :
(A) ohmic
(B) non-ohmic
(C) both
(D) sometimes ohmic, sometimes non-ohmic.
Answer:
(B) non-ohmic.
Question 30.
A wire of resistance 1 W is stretched to double its length. The resistance will become
(A) 1/4
(B) 1
(C) 2
(D) 4
Answer:
(D) 4
Question 31.
A car battery has emf 12 V and internal resistance 5 × 10-2 W. If it draws 60 A current, the terminal voltage of the battery will be
(A) 3 V
(B) 5 V
(C) 9 V
(D) 15 V
Answer:
(C) 9 V
Question 32.
The specific resistance of a wire depends upon :
(A) length
(B) cross sectional area
(C) mass
(D) none of these
Answer:
(D) None of these.
Question 33.
What is the unit for specific resistivity?
(A) Ohm-cm-2
(B) Ohm-cm1
(C) Ohm-cm
(D) Ohm-cm-2
Answer:
(C) Ohm-cm
Question 34.
A battery having emf 4 V and internal resistance 0.5 W is connected with a resistance of 4.5 W, then the voltage at the terminals of battery is :
(A) 4.5 V
(B) 3.6 V
(C) 0 V
(D) 2 V
Answer:
(B) 3.6 V
Question 35.
The unit of specific conductivity is:
(A) ohm-cm-1
(B) ohm-cm-2
(C) ohm-1-cm-1
(D) ohm-1 cm-2
Answer:
(C) ohm-1 cm-1
Question 36.
The length of a wire is doubled. Its conductance will be :
(A) unchanged
(B) halved
(C) doubled
(D) quadrupled
Answer:
(B) halved.
Question 37.
Practical unit of resistance is ohm is equal to :
(A) 109 emu
(B) 107 emu
(C) 1011 emu
(D) 1013 emu
Answer:
(A) 109 emu
Question 38.
How many electrons constitute current of IA?
(A) 6.25 × 109
(B) 6.25 × 1018
(C) 6.25 × 105
(D) 6.25 × 106
Answer:
(B) 6.25 × 1018
Question 39.
The resistance will be least in a wire with dimension
(A) L/2,2 A
(B) 2L, A
(C) L, A
(D) none of these
Answer:
(A) L/2,2A.
Question 40.
A cell of negligible resistance and emf 2V is connected to series combination of 2,3 and 5 ohm. The potential difference in vol across the 3 W resistance will be
(A) 6 V
(B) 3 V
(C) 2 / 3 V
(D) 0.6 V
Answer:
0.6 V
Question 41.
The material of a wire of a potentiometer is :
(A) copper
(B) steel
(C) manganin
(D) aluminium
Answer:
(C) magnanin.
Question 42.
Kirchhoff’s current law obeys conservation of :
(A) charge
(B) momentum
(C) energy
(D) none of these
Answer:
(A) charge.
Question 43.
Potentlometer measures potential more accurately because :
(A) It uses sensitive galvanometer for null deflection.
(B) It uses high resistance potentiometer wire.
(C) It measures the potential in the closed circuit.
(D) It measures the potential in the open circuit.
Answer:
(A) It uses sensitive galvanometer for null deflection.
Question 44.
A current loop placed in a magnetic field behaves like a:
(A) Magnetic dipole
(B) Magneitc substance
(C) Magnetic pole
(D) All are true
Answer:
(A) Magnetic dipole.
Question 45.
A charge + q is moving upwards vertically. It enters a magnetic field directed to the north. The force on the charged will be towards
(A) North
(B) South
(C) West
(D) East
Answer:
(C) West.
Question 46.
The vertical component of earth’s magnetic field is zero at a place where angle of dip is :
(A) 0°
(B) 45°
(C) 60°
(D) 90°
Answer:
(A) 0°
Question 47.
A magnetic needle suspended freely orients itself :
(A) in a definite direction
(B) in no direction
(C) upward
(D) downward
Answer:
(A) in a definite direction.
Question 48.
A material when placed in a magnetic field is thrown out of it. Then the material is :
(A) paramagnetic
(B) diamagnetic
(C) ferromagnetic
(D) non-magnetic.
Answer:
(B) diamagnetic.
Question 49.
Which of the following is an Ohmic resistance?
(A) diode value
(B) junction diode
(C) carbon-arc lamp
(D) nichrome
Answer:
(D) nichrome
Question 50.
For which of the following substances, resistance decreases with increase in temperature?
(A) copper
(B) mercury
(C) carbon
(D) platinum
Answer:
(C) carbon
Question 51.
In parallel combination of resistances –
(A) p.d. is same across each resistance
(B) total resistance is increased
(C) current is same in each resistance
(D) all of these are true
Answer:
(A) p.d. is same across each resistance
Question 52.
The main fuse is connected in :
(A) live wire
(B) neutral wire
C) both the live and earth wires
(D) both earth and neutral wire
Answer:
(A) live wire
Question 53.
The electric meter in a house records :
(A) charge
(B) current
(C) energy
(D) power
Answer:
(C) energy
Question 54.
When two negative charges are placed close together then :
(A) they attract each other
(B) they repel each other
(C) they become positive
(D) none of the above
Answer:
(B) they repel each other
Question 55.
If a source of EMF is traversed from negative to positive terminal, the potential change is :
(A) negative
(B) positive
(C) zero
(D) both negative\positive
Answer:
(B) positive
Question 56.
When the distance between the two charges are halved, the electrical force between the charges
(A) doubles
(B) reduces to one fourth
(C) halves
(D) quadraples
Answer:
(D) quadraples
Question 57.
Mercury behaves as a superconductor
(A) below 4.2K
(B) above 6.9 K
(C) below 23 K
(D) above 9.6 K
Answer:
(A) below 4-2 K
Question 58.
When a cell is in use, its emf E and terminal voltage v are related as :
(A) E = V
(B) E < V
(C) E > V
(D) none of these
Answer:
(C) E > V
Question 59.
Which one of the following behaves as a superconductor?
(A) platinum above 273 K
(B) mercury below 4.2K
(C) gold below -191°C
(D) fullerene at room temperature
Answer:
(B) mercury below 4.2K
Question 60.
If one of the resistors in a parallel circuit is removed, the total resistance will be :
(A) double
(B) same
(C) increased
(D) constant
Answer:
(C) increased
Question 61.
The flow of current in a circuit due to short circuit :
(A) reduces
(C) increases rapidly to dangerous level
(B) remains unchanged
(D) increases gradually
Answer:
(C) increases rapidly to dangerous level
Question 62.
If unit of I is ampere, unit of R is ohm, unit of t is second, then unit of H} is :
(A) Joule
(B) watt
(C) dyne / cm2
(D) ohm-1
Answer:
(A) Joule
Question 63.
The relation between H, I, R and t is :
(A) H = I2 R/t
(B) H/t = I2R
(C) R = I2 t/H
(D) I2 = HR/t
Answer:
(B) H/t = l2 R
Question 64.
The filament of an incandescent bulb is ma e up of :
(A) tungsten
(B) aluminium
(C) copper
(D) nichrome
Answer:
(A) tungsten
Question 65.
Which of the following properties is not suitable for a fuse wire?
(A) low melting point
(B) high resistance
(C) thick and short in length
(D) thin and short in length
Answer:
(C) thick and short in length
Question 66.
The commercial unit of electrical energy we use is :
(A) wh
(B) kwh
(C) kw
(D) kilowatt.second
Answer:
(B) kwh
Question 67.
If an electrical appliance has E E R = 3.1, it is rated as :
(A) 2 star
(B) 3 star
(C) 4 star
(D) 5 star
Answer:
(D) 5 star
Question 68.
The electric meter in a house records
(A) energy
(B) current
(C) power
(D) charge
Answer:
(A) energy
Question 69.
Which one among the following is most energy efficient ?
(A) CFL
(B) tube light
(C) LED
(D) Incandescent lamp
Answer:
(C) LED
Question 70.
In a parallel circuit of bulbs
(A) same current exists in all the bulbs
(B) voltage across each bulb remains the same
(C) failure of any bulb leads to a break in the circuit
(D) All the above
Answer:
(B) voltage across each bulb remains the same
Question 71.
A current carrying conductor produces
(A) electric field
(B) magnetic field
(C) both
(D) none of these
Answer:
(B) magnetic field
Question 72.
A split ring in motion is called :
(A) armature
(B) rotor
(C) core
(D) commutator
Answer:
(d) commutator
Question 73.
The direction of an induced current can be predicted by :
(A) Ampere’s swimming rule
(B) Fleming’s left hand rule
(C) Fleming’s right hand rule
(D) Right-hand thumb rule
Answer:
(C) Fleming’s right hand rule
Question 74.
The frequency of alternating current supplied in India is :
(A) OHz
(B) 50 Hz
(C) 110 Hz
(D) 220 Hz
Answer:
(B) 50 Hz
Question 75.
Lenz’s law supports the principle of conservation of :
(A) mass
(B) energy
(C) momentum
(D) charge
Answer:
(B) energy
Question 76.
In commercial alternators, the rotor consists of
(A) armature coil
(B) brushes
(C) field magnets
(D) none of these
Answer:
(C) field magnets
Question 77.
The commercial generation frequency in India is :
(A) 50 Hz
(B) 60 Hz
(C) 100 Hz
(D) 150 Hz
Answer:
(A) 50 Hz
Question 78.
DC generators are also called :
(A) dynamo
(B) inverter
(C) storage cell
(D) alternator
Answer:
(D) alternator
Question 79.
The potential difference between the live wire and the neutral wire in domestic circuit is :
(A) 220 V
(B) 11 KV
(C) 33 KV
(D) 132 KV
Answer:
(A) 220 V
Question 80.
A switch must be connected in
(A) neutral wire
(B) live wire
(C) earth wire
(D) either live wire or neutral wire
Answer:
(B) live wire
Question 81.
Which of the two wires of a household ctrcuit are at the same potential?
(A) Live and Neutral
(B) Live & Earth
(C) Neutral and Earth
(D) None of them
Answer:
(C) Neutral and Earth
Fill in the blanks :
1. Coulomb = _____ × second.
Answer:
ampere
2. The equivalent resistance is smaller than the resistance in a parallel combination of _____ resistances.
Answer:
smallest
3. Potential difference = current × ______.
Answer:
resistance
4. 12 rt is some electrical _____.
Answer:
work
5. Power = potential difference × ______.
Answer:
current
6. Resistance of a wire is _____ proportional to the length of the wire.
Answer:
directly
7. A _____ is used to measure the potential difference between two points in a section of an electrical circuit.
Answer:
voltmeter
8. An ammeter is used to measure the _____ flowing through an electric circuit where the ammeter is connected in series.
Answer:
current
9. Short circuit occurs due to accidental direct contact of the live and the _____ wires.
Answer:
neutral
10. The total resistance of a number of resistors in series is equal to the ______ of the resistances of the component resistors.
Answer:
sum
11. Elecctomotive force is some _____ not a force.
Answer:
energy
12. In current electricity, the potential difference between two points is measured by the work done when unit _____ flows from one point to the other.
Answer:
charge
13. Potential difference between two points one _____ when work done to carry one coulomb charge between the points be 1 Joule.
Answer:
volt.
14. Resistance is the natural property of every material body by virtue of which the body _____ flow of electric charges through it.
Answer:
opposes
15. The current flowing through a conductor is directly proportional to the potential difference between its ends when _____ and other physical conditions of the conductor remain unaltered.
Answer:
temperature
16. Ohm’s law is not valid for current flowing through _____ under low pressure, electrolytes and semi-conductors.
Answer:
gases
17. If an electrical instrument of power 1 watt works for 1 hour, the electrical energy expended is known as 1 _____.
Answer:
watt-hour
18. Number of B.O.T. unit = \(\frac{\text { amphere } \times \text { volt }}{1000}\) × _____.
Answer:
hour
19. When electric current does not change the direction it is called _____.
Answer:
Direct Current.
20. Watt = Volt × _______.
Answer:
Ampere
21. The electro magnets are made using the _____ effect of electric current.
Answer:
magnetic
22. Usually the resistance of a conductor _____ with the rise in temperature.
Answer:
increases
23. The SI unit of current is _____.
Answer:
ampere.
24. In Ohm’s law, the _____ and other physical conditions are remaining constant.
Answer:
temperature
25. The temperature remaining constant, the resistance between two opposite forces of a unit cube of a conductor is called its _____.
Answer:
specific resistance.
26. The watt-hour is the practical unit of _____ energy.
Answer:
electrical.
27. Like charges _____ each other.
Answer:
repel
28. SI unit of electric potential is _____.
Answer:
volt.
29. Electric fuse is a _____, device.
Answer:
safety
30. Fleming’s left hand rule is also called _____ rule.
Answer:
motor.
31. An electric generator converts _____ energy into electrical energy.
Answer:
mechanical.
32. The other name of potential difference is _____.
Answer:
voltage
33. The amount of energy given to each coulomb of charge passing through a 12 V battery is _____ J.
Answer:
12
34. The unit of \varepsilon_0 (permitivity in vacuum) is _____.
Answer:
C2 N-1 m-2
35. Resistivity of silver _____ with increase in temperature.
Answer:
increases
36. An ideal cell should have _____ internal resistance.
Answer:
zero
37. Mica is an _____.
Answer:
insulator
38. _____ filament is used in incandescent bulb.
Answer:
tungsten
39. Tube-lights are _____ power efficient than incandescent bulbs.
Answer:
more
40. CFLs and LED bulbs are _____ efficient than filament-type bulb.
Answer:
more
41. More the number of stars in an electrical appliance, _____ is its efficiency.
Answer:
higher
42. SI unit of magnetic field strength is _____.
Answer:
Tesla
43. The magnetic effect of current was discovered by _____.
Answer:
Oersted
44. The direction of induced current can be predicted by _____ law.
Answer:
Lenz’s
45. Laws of electromagnetic induction was proposed by _____.
Answer:
Faraday
46. In our houses, we have electric supply of frequency _____ Hz.
Answer:
50
47. In an alternator, the stator consists of the _____.
Answer:
armature.
48. The house wiring is done in a ______ system.
Answer:
tree
49. The earth wire should be connected to the _____ of the appliance.
Answer:
body
State whether the following statement is True or False : VSA
1. An ammeter is connected in series in a circuit and a voltmeter is connected in parallel.
Answer:
True
2. Electric current is the flow of charge.
Answer:
True
3. Electric current is vector quantity.
Answer:
False
4. All types of conductors obey ohma’s law
Answer:
False
5. Below 4.2K, mercury behaves as a superconductor.
Answer:
True
6. Resistance of materials in superconducting state is infinity high.
Answer:
False
7. If current flowing through a wire is doubled, the heat produced will also be doubled.
Answer:
False
8. An incandescent bulb is an energy efficient bulb.
Answer:
False
9. Watt is a much smaller unit of electrical power.
Answer:
True
10. We should buy electrical appliance with lower star-rating.
Answer:
False
11. Barlow’s wheel works on alternating current.
Answer:
False
12. At the centre of the circular loop, the magnetic field line is straight.
Answer:
True
13. Lenz’s law is in accordance with the law of conservaion of energy.
Answer:
True
14. A direct current can be stepped up for transmission.
Answer:
False
15. The earth is considered to be at zero potential.
Answer:
True