# WBBSE Class 10 Physical Science MCQ Questions Chapter 6 Current Electricity

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
((A) Coulomb

Question 2.
The unit of potential difference is :
(A) joule
(B) volt
(C) ohm
(E) ampere
(B) volt

Question 3.
The unit of electrical power is:
(A) volt
(B) watt
(C) ohm
(D) joule
(B) wait

Question 4.
What material an electric fuse made of?
(A) copper
(B) silver
(C) iron

Question 5.
Unit of resistance is:
(A) ampere
(B) ohm
(C) coulomb
(D) joule
(B) ohm

Question 6.
Specific resistance of a conductor dipends on :
(A) its length
(B) its cross-sectional area
(C) its material
(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
(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
(B) electric motor

Question 9.
The action of electric current on magnet was first observed by:
(A) Oerested
(B) Joule
(C) Barlow
(D) Newton
(A) Oerested

Question 10.
Ohm’s law is related to:
(A) current and potential difference
(B) volume and pressure
(C) temperature density.
(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
(C) B.OT inits

Question 12.
Which one is not conductor of electricity:
(A) copper
(B) gold
(C) aluminium
(D) plastic
(D) plastic

Question 13.
Ammeter measures:
(A) resistance
(B) potential difference
(C) current
(C) current

Question 14.
Potential difference is measured by:
(A) Voltmeter
(B) Volameter
(C) Galvanometer
(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
(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
(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
(C) Watt = Volt × Ampere

Question 18.
The physical quantity measured by kilowatt-hour
(A) Electric power
(B) Electric energy
(C) Current
(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
(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
(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
(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]
(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.
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
(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
(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
(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
(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
(C) 6 V

Question 29.
The resistance of discharge tube is :
(A) ohmic
(B) non-ohmic
(C) both
(D) sometimes ohmic, sometimes non-ohmic.
(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
(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
(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
(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
(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
(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
(C) ohm-1 cm-1

Question 36.
The length of a wire is doubled. Its conductance will be :
(A) unchanged
(B) halved
(C) doubled
(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
(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
(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
(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
0.6 V

Question 41.
The material of a wire of a potentiometer is :
(A) copper
(B) steel
(C) manganin
(D) aluminium
(C) magnanin.

Question 42.
Kirchhoff’s current law obeys conservation of :
(A) charge
(B) momentum
(C) energy
(D) none of these
(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.
(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
(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
(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°
(A) 0°

Question 47.
A magnetic needle suspended freely orients itself :
(A) in a definite direction
(B) in no direction
(C) upward
(D) downward
(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.
(B) diamagnetic.

Question 49.
Which of the following is an Ohmic resistance?
(A) diode value
(B) junction diode
(C) carbon-arc lamp
(D) nichrome
(D) nichrome

Question 50.
For which of the following substances, resistance decreases with increase in temperature?
(A) copper
(B) mercury
(C) carbon
(D) platinum
(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
(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
(A) live wire

Question 53.
The electric meter in a house records :
(A) charge
(B) current
(C) energy
(D) power
(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
(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
(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

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
(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
(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
(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
(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
(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
(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
(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
(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
(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
(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
(D) 5 star

Question 68.
The electric meter in a house records
(A) energy
(B) current
(C) power
(D) charge
(A) energy

Question 69.
Which one among the following is most energy efficient ?
(A) CFL
(B) tube light
(C) LED
(D) Incandescent lamp
(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
(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
(B) magnetic field

Question 72.
A split ring in motion is called :
(A) armature
(B) rotor
(C) core
(D) commutator
(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
(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
(B) 50 Hz

Question 75.
Lenz’s law supports the principle of conservation of :
(A) mass
(B) energy
(C) momentum
(D) charge
(B) energy

Question 76.
In commercial alternators, the rotor consists of
(A) armature coil
(B) brushes
(C) field magnets
(D) none of these
(C) field magnets

Question 77.
The commercial generation frequency in India is :
(A) 50 Hz
(B) 60 Hz
(C) 100 Hz
(D) 150 Hz
(A) 50 Hz

Question 78.
DC generators are also called :
(A) dynamo
(B) inverter
(C) storage cell
(D) alternator
(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
(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
(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
(C) Neutral and Earth

Fill in the blanks :

1. Coulomb = _____ × second.
ampere

2. The equivalent resistance is smaller than the resistance in a parallel combination of _____ resistances.
smallest

3. Potential difference = current × ______.
resistance

4. 12 rt is some electrical _____.
work

5. Power = potential difference × ______.
current

6. Resistance of a wire is _____ proportional to the length of the wire.
directly

7. A _____ is used to measure the potential difference between two points in a section of an electrical circuit.
voltmeter

8. An ammeter is used to measure the _____ flowing through an electric circuit where the ammeter is connected in series.
current

9. Short circuit occurs due to accidental direct contact of the live and the _____ wires.
neutral

10. The total resistance of a number of resistors in series is equal to the ______ of the resistances of the component resistors.
sum

11. Elecctomotive force is some _____ not a force.
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.
charge

13. Potential difference between two points one _____ when work done to carry one coulomb charge between the points be 1 Joule.
volt.

14. Resistance is the natural property of every material body by virtue of which the body _____ flow of electric charges through it.
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.
temperature

16. Ohm’s law is not valid for current flowing through _____ under low pressure, electrolytes and semi-conductors.
gases

17. If an electrical instrument of power 1 watt works for 1 hour, the electrical energy expended is known as 1 _____.
watt-hour

18. Number of B.O.T. unit = $$\frac{\text { amphere } \times \text { volt }}{1000}$$ × _____.
hour

19. When electric current does not change the direction it is called _____.
Direct Current.

20. Watt = Volt × _______.
Ampere

21. The electro magnets are made using the _____ effect of electric current.
magnetic

22. Usually the resistance of a conductor _____ with the rise in temperature.
increases

23. The SI unit of current is _____.
ampere.

24. In Ohm’s law, the _____ and other physical conditions are remaining constant.
temperature

25. The temperature remaining constant, the resistance between two opposite forces of a unit cube of a conductor is called its _____.
specific resistance.

26. The watt-hour is the practical unit of _____ energy.
electrical.

27. Like charges _____ each other.
repel

28. SI unit of electric potential is _____.
volt.

29. Electric fuse is a _____, device.
safety

30. Fleming’s left hand rule is also called _____ rule.
motor.

31. An electric generator converts _____ energy into electrical energy.
mechanical.

32. The other name of potential difference is _____.
voltage

33. The amount of energy given to each coulomb of charge passing through a 12 V battery is _____ J.
12

34. The unit of \varepsilon_0 (permitivity in vacuum) is _____.
C2 N-1 m-2

35. Resistivity of silver _____ with increase in temperature.
increases

36. An ideal cell should have _____ internal resistance.
zero

37. Mica is an _____.
insulator

38. _____ filament is used in incandescent bulb.
tungsten

39. Tube-lights are _____ power efficient than incandescent bulbs.
more

40. CFLs and LED bulbs are _____ efficient than filament-type bulb.
more

41. More the number of stars in an electrical appliance, _____ is its efficiency.
higher

42. SI unit of magnetic field strength is _____.
Tesla

43. The magnetic effect of current was discovered by _____.
Oersted

44. The direction of induced current can be predicted by _____ law.
Lenz’s

45. Laws of electromagnetic induction was proposed by _____.

46. In our houses, we have electric supply of frequency _____ Hz.
50

47. In an alternator, the stator consists of the _____.
armature.

48. The house wiring is done in a ______ system.
tree

49. The earth wire should be connected to the _____ of the appliance.
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.
True

2. Electric current is the flow of charge.
True

3. Electric current is vector quantity.
False

4. All types of conductors obey ohma’s law
False

5. Below 4.2K, mercury behaves as a superconductor.
True

6. Resistance of materials in superconducting state is infinity high.
False

7. If current flowing through a wire is doubled, the heat produced will also be doubled.
False

8. An incandescent bulb is an energy efficient bulb.
False

9. Watt is a much smaller unit of electrical power.
True

10. We should buy electrical appliance with lower star-rating.
False

11. Barlow’s wheel works on alternating current.
False

12. At the centre of the circular loop, the magnetic field line is straight.