MCQs on Current Electricity (Physics) with Answers

In this article you can find 100 Multiple Choice Questions Related to Current Electricity of Physics with answers. This will be useful for students and faculty members.
Multiple Choice Questions with Answers
1 Electric current originates from which part of an atom?
A. nucleus
B. entire atom acting as a unit
C. positively charged protons
D. negatively charged electrons
Ans: D
Electric current originates from negatively charged electrons
2 Which of the following is true of electrical forces?
A. Like charges attract, unlike charges repel.
B. Electrical forces are produced by electrical charges.
C. Positive and negative charges can combine to produce a third type
D. Electrical forces are weaker than gravitational forces.
Ans: B
Electrical forces are produced by electrical charges
3 How can electric charge be established?
A. Electrons can be removed from atoms and accumulated to produce a negative charge.
B. Atoms from which electrons have been removed produce positive electric charge.
C. Both A and B.
D. Neither A nor B.
Ans: C
Electrons have been removed produce positive electric charge & a negative charge
4 When a person combs her hair, static electricity is sometimes generated by what process?
A. Friction between the comb and hair transfers electrons.
B. Induction between the comb and hair.
C. Deduction between the comb and hair.
D. Contact between the comb and hair results in a charge.
Ans: A
static electricity is sometimes generated by Friction
5 The resistance of the wire varies inversely as:
A. Area of cross section
B. Resistivity
C. Length
D. Temperature
Ans: A
The resistance of the wire varies inversely as Area of cross section
6 Voltage is a form of:
A. Kinetic energy
B. Potential energy
C. both Potential and Kinetic energy
D. None of the above
Ans: B
Voltage is a form of Potential energy
7 The ratio of voltage and electrical current in a closed circuit:
A. Decreases
B. Increases
C. Remains constant
D. Varies
Ans: C
The ratio of voltage and electrical current in a closed circuit Remains constant
8 The curve representing Ohms law is a:
A. Linear
B. cosine function
C. Parabola
D. Hyperbola
Ans: A
The curve representing Ohms law is a Linear
9 Ohm’s law states which relationship between electrical quantities?
A. volts = current times resistance
B. volts = current divided by amps
C. volts = coulombs divided by charge
D. volts = resistance times charge
Ans: A
volts = current times resistance
10 Resistance is a measure of a material’s opposition to
A. voltage
B. current
C. electric force.
D. movement of protons.
Ans: B
Resistance is a measure of a material’s opposition to current
11 Electric current is defined as a flow of
A. electric charge in units of volts per s.
B. protons in units of protons per s.
C. electric charge in units of coulomb per s.
D. electrons in units of electrons per s.
Ans: C
electric charge in units of coulomb per s
12 What are the basic components of a simple electric circuit?
A. energy source
B. connecting wires
C. switch
D. All the above
Ans: D
energy source, wires, and switch are the basic components
13 To produce a electric current what is the requirement?
A. A voltage source
B. A source of energy that moves charges
C. An electric field moving through a conductor
D. Any of the above
Ans: D
to produce a sustained electric current A source of energy, A voltage source An electric field is required
14 Which of the following is not an electrical classification of materials?
A. Semiconductors
B. Semi-insulators
C. Insulators
D. Conductors
Ans: B
Semi-insulators, which sometimes conduct and sometimes insulate
15 Give the name of materials which contain lots of free electrons.
A. insulators
B. conductors
C. semiconductors
D. None of the above
Ans: B
In an atom the free electrons are present at outermost orbit.It can easily flow from one atom to another by applying voltage. So it is called as conductor.
16 Which of the following is not a type of energy source?
A. generator
B. solar cell
C. rheostat
D. battery
Ans: C
“Generator = Mechanical Energy to Electrical Energy,
Solar cell = Light energy to Electrical Energy,
battery = Chemical energy to Electrical Energy.
Rheostat = Variable resistance
17 When two positively charged materials will placed close together then :
A. it will repel each other
B. become negative
C. it will attract each other
D. None of the above
Ans: A
Like charge Repel each other
18 Electrons in the outer orbit are called
A. shells
B. valences
C. nuclei
D. All the above
Ans: B
Electrons in the outer orbit are called valences
19 A series circuit consists of three resistors with values of 140 , 250 , and 220 . The total resistance is
A. 330
B. 610
C. 720
D. None of the above
Ans: B
Series means current is same so all resistors are added
140 + 250 + 220 = 610
20 When will be the current flows in a circuit?
A. a switch is closed
B. a switch is opened
C. switch is either open or closed
D. None of the above
Ans: A
When switch is closed in any circuit it acts as a closed circuit so current flows only in a closed circuit.
21 The unit of electrical charge is the
A. coulomb
B. volt
C. joule
D. watt
Ans: A
1 coulomb is the charge carried carried by 6.25*10^18 electrons
22 When one of three series resistors is removed from a circuit and the circuit is reconnected, the current
A. increases by half
B. increases
C. decreases by half
D. None of the above
Ans: B
When resistance decreases, the current increases. Because R=V/I, resistance and current are inversely proportional.
23 If a 24 V and a 10 V battery are series opposing, the total voltage is
A. 14 V
B. 10 V
C. 24 V
D. 34 V
Ans: A
v1-V2 (i.e): 24-10=14v.
24 A series circuit consists of three resistors. Two resistors are 1.4 k each. The total resistance is 12 k. The value of the third resistor
A. 92 k ohm
B. 920 ohm
C. 9200 ohm
D. None of the above
Ans: C
r1+r2+r3=R
1.4 +1.4 + X=12
x=9.2 Kilo ohm
9200 ohm
25 A 430 resistor, a 210 resistor, and a 100 resistor are all in parallel. The total resistance is :
A. 0.017 ohm
B. 58.82 ohm
C. 58.82 kilo ohm
D. None of the above
Ans: B
1/R = (1/430 + 1/210 + 1/100)
R = 58.82 ohm
26 The SI unit of power is_________.
A. Joule
B. Ampere
C. Watt
D. Ohm
Ans: C
The SI unit of power is Watt
27 According to Ohm’s law, if voltage increases and resistance stays the same:
A. resistance decreases
B. current increases
C. current remains the same
D. current decreases
Ans: B
V=IR
SO if resistance constant, AND if voltage increases Then current also increases because proportional to each other
28 The instrument used for measuring electric current is :
A. galvanometer
B. ammeter
C. voltmeter
D. potentiometer
Ans: B
The instrument used for measuring electric current is ammeter
29 The amount of work done in joules, when one unit electric charge moves from one point to another point in an electric circuit is called :
A. resistance
B. potential difference
C. current
D. charge
Ans: B
The amount of work done in joules, when one unit electric charge moves from one point to another point in an electric circuit is called potential difference
30 The resistance of material depends on :
A. temperature
B. length of conductor
C. area of cross-section
D. All the above
Ans: D
31 The relation between potential difference (V) and current (I) is :
A. V α I
B. V α I2
C. V α 1/I
D. None of the above
Ans: A
V α I , V=IR
32 The relation between potential difference (V) and current (I) was discovered by :
A. Volt
B. Ohm
C. Newton
D. Ampere
Ans: B
The relation between potential difference (V) and current (I) was discovered by Ohm
33 What is the most commonly used conductor in electronics?
A. copper
B. aluminum
C. gold
D. silver
Ans: A
34 Give the name of components which is designed to oppose the flow of current.
A. capacitor
B. resistors
C. inductor
D. EMF
Ans: B
35 What are the different parts of a rheostat?
A. only wiper
B. wiper and resistor track
C. armature
D. oly resistor track
Ans: B
36 The SI unit of electric current is :
A. ohm
B. volt
C. ampere
D. watt
Ans: C
The SI unit of electric current is ampere
37 The rate of flow of an electric charge is known as :
A. electric potential
B. electric resistance
C. electric current
D. None of the above
Ans: C
The rate of flow of an electric charge is known as electric current
38 An ideal voltmeter would have an:
A. Infinite resistance
B. Very low resistance
C. Double the resistance
D. Resistance equal to the circuit
Ans: A
An ideal voltmeter would have an Infinite resistance
39 Resistance ‘R’ of a wire of length “L” is given by the relation:
A. R=L/Ρa
B. R=L/A
C. R=ρL/A
D. None of the above
Ans: C
Resistance ‘R’ of a wire of length “L” is given by the relation R=ρL/A
40 The unit of emf is ___________.
A. volt
B. Joule
C. Ampere
D. Watt
Ans: A
The unit of emf is Volt
41 If a source of EMF is traversed from negative to positive terminal the potential change is:
A. Negative
B. Positive
C. Positive and Negative Both
D. None of the above
Ans: B
If a source of EMF is traversed from negative to positive terminal the potential change is Positive
42 The resistance of a conductor is directly proportional to :
A. Length
B. Area
C. volt
D. current
Ans: A
The resistance of a conductor is directly proportional to length
43 Which of the following laboratory apparatus is used during the verification of Ohm’s law ?
A. Voltmeter
B. Ammeter
C. Rheostat
D. All the above
Ans: D
44 Positive electrode is known as__________.
A. Cathode
B. Anode
C. Anode tube
D. Cathode tube
Ans: B
45 When the pointer of an analog ohmmeter reads close to zero, the resistor being measured is:
A. open
B. reversed
C. shorted
D. overheated
Ans: C
r=0 when short circuited
r=infinity(high) when open circuited.
46 Which of the following is a six basic forms of energy ?
A. light, sun, magnetic, chemical, electrical, and mechanical
B. electrical, mechanical, light, heat, magnetic, and chemical
C. potential, sun, light, chemical, electrical, and mechanical
D. electrical, mechanical, sun, heat, chemical, and light
Ans: B
47 The word work means that:
A. energy has been transferred
B. no energy has been transferred
C. it is inversely related to energy
D. None of the above
Ans: A
48 Kilowatt – hour is the unit of:
A. power
B. potential difference
C. Force
D. electrical energy
Ans: D
49 If resistance decreases, then current will:
A. increase
B. double
C. decrease
D. Constant
Ans: A
Since, I=V/R.
Resistance is inversely proportional to current.
50 The resistance of a conductor is inversly proportional to its :
A. volt
B. Length
C. Area
D. None of the above
Ans: B
The resistance of a conductor is inversely proportional to its area of cross-section
51 Which type of test equipment is used to measure resistors?
A. ohmmeter
B. ammeter
C. voltmeter
D. wattmeter
Ans: A
52 Why battery is used in the circuit ?
A. measure current
B. maintain a potential difference
C. oppose the current
D. measure potential
Ans: B
53 What will be the equivalent e.m.f of the battery if three cells each of e.m.f ‘E’ are joined in parallel ?
A. E
B. E= 0
C. 3E
D. E /3
Ans: A
54 Electric cell is a device which converts energy from ………… to …………..
A. elctrical to chemical
B. elctrical to mechanical
C. chemical to elctrical
D. mechanical to elctrical
Ans: C
55 For the verification of Ohm’s law ammeter and voltmeter should be connected in :
A. ammeter and voltmeter should be connected in parallel
B. ammeter should be connected in parallel and voltmeter in series
C. ammeter and voltmeter should be connected in series
D. ammeter should be connected in series and voltmeter in parallel
Ans: D
ammeter should be connected in series and voltmeter in parallel
56 Why rheostat is used in the circuit ?
A. increase the magnitude of current
B. increase or decrease the magnitude of current
C. decrease the magnitude of current only
D. None of the above
Ans: B
57 A current of 3A flows through a conductor whose ends are at a p.d of 6V. Calculate the resistance of the conductor ?
A. ohm
B. 0.5 ohm
C. 2 ohm
D. 12 ohm
Ans: C
V= IR, R= V/I, R= 6/3 =2 ohm
58 Rubber is material included in :
A. insulators
B. conductors
C. semiconductors
D. None of the above
Ans: A
59 How many terminal electric cell consists of ?
A. one
B. three
C. two
D. four
Ans: C
60 Electrical conductors are materials which contain:
A. only positive charge
B. movable electric charge
C. only negative charge
D. None of the above
Ans: B
In case of metallic conductors like copper or aluminum the movable charge particles are electrons
61 Insulator material is used for :
A. protecting from shock
B. provide the current
C. oppose the current
D. None of the above
Ans: A
62 In series combination, resistance increases due to increase in :
A. Area of cross-section
B. Voltage
C. Length
D. Current
Ans: C
63 Conductance is expressed in terms of :
A. mho.
B. ohm / m
C. ohm
D. mho / m
Ans: A
64 If there are three resistances each of 2 ohm and generate the effective resistance of 3 ohm so how will the connection of the three resistances in the circuit?
A. A parallel combination of two resistances and one in series
B. A series combination of two resistances and one in parallel
C. Three are in series
D. Three are in parallel
Ans: A
A parallel combination of two resistances (which will be 1 ohm) joined in series with the third resistance (2 ohm)
65 What happen when ammeter connected in parallel ?
A. open circuited
B. closed circuited
C. short circuited.
D. None of the above
Ans: C
Ammeter consists of a wire of low resistance when connected in parallel, a large amount of current passes through it hence gets burnt i.e. short circuited.
66 If two unequal resistors connected in parallel then
A. The voltage is same in both resistor
B. The current is same in both resistor
C. The voltage is large in one of the resistor
D. The current is large in one of the resistor
Ans: A
67 Which of the following is good conductor of electricity ?
A. aluminum
B. wood
C. plastic
D. cloth
Ans: A
68 What does a switch do ?
A. oppose the current
B. open and closed the circuit
C. provide current
D. store the energy
Ans: B
69 If there is two bulb i.e 150W bulb and 60W bulb so which has more resistance ?
A. 60 W
B. 150W
C. Both A and B.
D. None of the above
Ans: A
As R is inversely proportional to P for constant V. Thus, the resistance of 60W bulb is more.
70 If resistance of a wire is r ohms and wire is stretched to double its length, then what is its resistance ?
A. r
B. 2 r
C. 4 r
D. r/2
Ans: C
71 In parallel combination, resistance decreases due to increase in
A. Area of cross-section
B. Voltage
C. Length
D. current
Ans: A
72 Which of the following is bad conductor of electricity ?
A. Gold
B. plastic
C. silver
D. copper
Ans: B
73 The device which easily closes or opens an electric circuit is called as:
A. switch
B. cell
C. key
D. bulb
Ans: A
74 A small wire present inside the bulb is called as:
A. conductor
B. Filament
C. Insulators
D. None of the above
Ans: B
75 If one of the resistors in a parallel circuit is removed, the total resistance will be :
A. doubles
B. decreases
C. increases
D. constant
Ans: C
When the resisters are connected in series resistance of the circuit will be more than the resisters are connected in parallel. Parallel resistor is removed from the circuit the resistance will increase.
76 All good conductors have high :
A. resistance
B. conductance
C. voltage
D. None of the above
Ans: B
77 A short circuit has:
A. no resistance
B. no conductance
C. low current
D. None of the above
Ans: A
78 Combination of three resistances in series then it is given as:
A. R1 + R2 + R3
B. 1/R1 + 1/ R2 + 1/ R3
C. R1 x R2 x R3
D. None of the above
Ans: A
79 A parallel circuit is also used as a divider for:
A. power
B. Resistance
C. Current
D. Voltage
Ans: C
Current remains same in series circuit and changes in parallel circuit.
80 What happens to current and resistance if the voltage doubles?
A. Current doubles and resistance doubles
B. Current doubles and resistance is halfed.
C. Current remains the same and resistance doubles.
D. Current doubles and resistance remains the same.
Ans: D
V=IR
I=V/R
I=2V/2R–>V/R
Current remains same while in our case resistance is doubles.
81 What should be the resistance of an Voltmeter ?
A. zero
B. infinity
C. negligible
D. None of the above
Ans: B
The resistance of a voltmeter should be very high and for an ideal voltmeter, its value is infinity.
82 If the resistance total in a series circuit doubles, current will:
A. Doubles
B. Half
C. same
D. increases
Ans: B
if the resistance is doubled then the current will be i=v/2r
83 Which is considered to be the common reference for a parallel circuit?
A. Current
B. Resistance
C. Power
D. Voltage
Ans: D
Voltmeter is always connected in parallel.
84 When a battery is connected to a series circuit, it delivers current based only upon:
A. primary/secondary difference
B. the polarity connections
C. total resistance
D. average resistance
Ans: C
When a battery is connected to a series circuit, it delivers current based only upon total resistance
85 The symbol given for ohm is
A. Ω
B. Ʊ
C. ohm
D. None of the above
Ans: A
86 Why are copper wires used as connecting wires?
A. low resistivity
B. low conductivity
C. High resistivity
D. Both A and B
Ans: A
87 Direction of conventional current is from:
A. Negative terminal to positive terminal
B. In both the directions
C. Positive terminal to negative terminal
D. None of the above
Ans: C
88 A current of 2A flows through a 12V bulb then calculate the resistance ?
A. 6 ohm
B. 0.16 ohm
C. 32 ohm
D. ohm
Ans: A
I = 2A, V = 12 volts, V=IR
89 A cell or battery maintained a difference in potential between its two electrodes by the :
A. mechanical processes
B. electrical processes
C. chemical processes
D. None of the above
Ans: C
90 The conductors which do not obey ohm’s law is called as:
A. un-ohmic conductors.
B. non-ohmic conductors.
C. low-ohmic conductors.
D. zero- ohmic conductors.
Ans: B
The conductors which do not obey ohm’s law are called non-ohmic conductors.
91 The cylindrical container of electric cell is made up of which material.
A. copper
B. aluminum
C. iron
D. Zinc
Ans: D
92 Conductivity is the ____________ of resistivity.
A. opposite
B. Reciprocal
C. equal
D. None of the above
Ans: B
Conductivity is the Reciprocal of resistivity.
93 1 Ampere is given as:
A. 1 C x 1s
B. 1 C/1s
C. 1s / 1 C
D. None of the above
Ans: B
flow of one coulomb charge per second.
94 On which of the following device there is marked of plus and minus sign.
A. ammeter
B. voltmeter
C. battery
D. All the above
Ans: D
95 Which oft following relation is correct for voltage, work done and charge ?
A. V = W x Q
B. V = W / Q
C. V = Q / W
D. W = V/ Q
Ans: B
96 A complete electric circuit is called as:
A. open
B. short
C. closed
D. complete
Ans: C
97 How many terminals an electric bulb consists of ?
A. 2
B. 4
C. 3
D. 1
Ans: A
98 If two resistors have the same voltage drop in a series circuit, it means:
A. voltage has doubled
B. equal value
C. unequal value
D. not determine
Ans: D
In series circuit I is same in all resistor.
ie IxR1=IxR2
only if R1=R2
99 What should be the resistance of an ammeter?
A. zero
B. infinity
C. negligible
D. None of the above
Ans: A
The resistance of an ammeter should be very small and for an ideal ammeter, its value is zero.
100  How is the potential difference maintained across the ends of a conductor?
A. by connecting rheostat
B. by connecting it to a battery or a dry cell
C. by connecting resistance
D. by connecting switch
Ans: B

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