Physics Part-II Chapter 3 Current Electricity MCQ Practice

  1. What is the value of equivalent resistance if 50 Resistors of 5 ohm resistance are connected in Series (a) 10 Ohm   (b) 250 Ohm         (c) 50 Ohm (d) 500 Ohm
  2. What is the value of unknown Resistor R, If galvanometer shows null deflection in the given meter bridge set up?   (a) 97.5 Ohm       (c)  105 Ohm    (c) 150 Ohm         (d) 110 Ohm
    • In the shown figure, bridge is balanced, the current flowing through 2 Ohm resistance is    (a) 10/7 A      (b) 17/7 A         (c) 11/7 A        (d) 8/7 A
    • In a Wheatstone Network, P=2 Ohm, Q= 2 Ohm, R=2 Ohm & S=3 Ohm. The resistance with which S is to be shunted in order that the bridge may be balanced is (a) 1 Ω    (b) 2 Ω   (c) 4 Ω        (d) 6 Ω
    • Kirchhoff s second law is based on the law of conservation of    (a) charge            (b) mass
      (c) energy         (d) momentum
    • A wire has a resistance of 6 Ω. It is cut into two parts and both half values are connected in parallel. The new resistance is –      (a) 12 Ω    (b) 1.5 Ω      (c) 3 Ω     (d) 6 Ω
    • When there is an electric current through a conducting wire along its length, then an electric field must exist: (a) outside the wire but normal to it.  (b) inside the wire but parallel to it. (c) inside the wire but normal to it. (d) outside the wire but around it.
    • The terminal potential difference of a cell when short circuited is  (a) zero     (b) E      (c) E/2        (d) E/3
    • For which of the following dependence of drift velocity electric field E is Ohm’s law obeyed. (a) vd < √E             (b) vd ∝ E
      (c) vd ∝ E²             (d) vd = constant
    • In 10 minutes, 3000 Coulombs of free electrons enter one end of a conductor and 3000 Coulomb of then leave the conductor at its other end. The current in the conductor is: (a) 5 A      (b) 10 A    (c) 0 A   (d) 30 A
    • A current I flows in a wire of circular cross-section with the free electrons travelling with a drift velocity v. The drift velocity of electrons when a current 21 flows in another wire of twice radius and of the same material is: (a) v/2      (b) v        (c) 2v     (d) √2 v
    • Three equal registers connected in series across a source of e.m.f. together dissipate 10 watts of power. What would be the power dissipated if the same resistors are connected in parallel across the same source of e.m.f.? (a) 9 watts                  (b) 90 watts
      (c) 10 watts                (d) 100 watts
    • The temperature coefficient of resistance of a wire is 0.00125°C-1.At 27°C, its resistance is 1Ω. The temperature of the wire at which its resistance becomes 2Ω is:  (a) 1400 K                (b) 854°C
      (c) 1127 K                (d) 1154 K.
    • The heating element of an electric heater should be made of a material that should have: (a) low specific resistance and low melting point.
      (b) high specific resistance and high melting point.
      (c) high specific resistance and low melting point.
      (d) low specific resistance and high melting point.
    • The effective wattage of 60 W and 40 W lamps connected in: (A) series is equal to: (a) 24W    (b) 20W    (c) 100W    (d) 80W
    • If above lamps are connected in parallel is equal to: (a) 24W    (b) 20W   (c) 100W  (d) 80W
    • In an experiment to measure the internal resistance of a cell by a potentiometer, it is found that the balance point is at a length of 2 m, when the cell is shunted by a 5Ω resistance and is at 3 m when the cell is shunted by a 10Ω resistance. The internal resistance of the cell is: (a) 10Ω   (b) 15Ω   (c) 1Ω   (d) 1.5Ω
    • The rate of flow of electric charge through any cross-section of a conductor is known as __. (a) Electric flux        (b) Electric current  (c) Electric potential    (d)Electric field
    • Which of the following is non-ohmic resistance?   (a) Lamp filament     (b) Carbon resistor    (c) Copper wire       (d) Diode
    • Current density is a __________.     (a) scalar quantity.   (b) vector quantity.   (c)dimensionless quantity.   (d) none of these options
    • The resistivity of certain metals or alloys drops to zero when they are cooled below a certain temperature, this phenomenon is known as _____   (a) Conductivity   (b) Partial conductivity  (c) Superconductivity   (d)Non-conductivity
    • State true or false: The total resistance in the series combination is more than the greatest resistance in the circuit.   (a) True                    (b) False
    • The opposition offered by the electrolyte of the cell to the flow of current through itself is known as __________.    (a) External resistance  (b) Internal resistance (c) Non-resistance (d) None of these options
    • The resistance of the wire varies inversely as:   (a) Area of cross section   (b)Resistivity (c) Length                (d) Temperature
    • The curve representing Ohms law is a:   (a) Linear              (a)  cosine function  (c) Parabola            (d) Hyperbola
    • The resistance of a conductor depends upon  (a) Nature of the conductor (b)The dimension of the conductor (c )The physical state of the conductor (d) All of above
    • A wire of uniform area of cross-section A length L and resistance R is cut into two parts. The resistivity of each part    (a) Remains the same  (c) Is doubled (b) Is halved        (d) Becomes zero
    • When the same current passes for the same time through a thick and thin wire (a) More heat is produced in a thick wire   (b) More heat is produced in a thin wire (c)No heat is produced in the wire (d) Less heat is produced in a thick wire
    • How much heat does a 40 W bulb generates in one hour?   (a) 144000J             (c)144J 1.44J                  (d) 14J
    • An immersion heater of 400 watts kept on for 5 hours will consume electrical power of (a) 2KWh               (c) 20KWh (b) 6KWh               (d) 12KWh
    • The resistance of a superconductor is     (a) Finite  (b)Infinite      (c)Zero   (d) Changes with every conductor
    • Reciprocal of resistivity is called    (a) Resistance       (b)Inductance   (c)Conductivity   (d)Flexibility
    •  There are three bulbs of 60W 100W and 200W which bulb has the thickest filament.  (a) 100W   (b) 200W   (c) 60W  (d) All
    • The specific resistance of a wire    (a) Will depend on its length (b)Will depend on its radius (c) Will depend on the type of material of the wire (d) Will depend on none of the above
    • In liquids and gases, the current is due to the motion  (a) Negative charges (b) Positive charges (c) Both negative and positive charges (d) Neutral Particles
    • If 1 ampere current flows through 2m long conductor the charge flow through it in 1 hour will be    (a) 3600C                 (c) 7200C   (b) 1C                       (d) 2C
    • Which one of the following material is useful for making bulb filaments? (a) Constantan          (b) Nichrome (c) Copper                 (d) Tungsten
    • Electrical energy is measured in (a) Watt                    (b) Horse power (c) Kilowatt (d)Kilowatt-hour
    • A fuse is placed in series with the circuit to protect against  (a) High power         (b) High voltage   (c) High current       (d) Over heating
    • The direction of flow of current through electric circuit is  (a) From low potential to high potential   (b) From high potential to low potential     (c) Does not depends upon the potential value   (d) Current cannot floe through circuit
    • Equivalent resistance of the given circuit in ohm is-    (a) 28      (b) 5      (c) 11    (d) 11/8
    • Equivalent resistance of the given circuit in ohm is-  (a) 9       (b) 2          (c)7     (d) 4.5
    • Determine the current through R1 Resistor in Ampere, if R1=44 ohm R2=30 Ohm R3=15 Ohm & = 12 Volt    (a) 2/9 A      (b)9/2 A      (c) 9A    (d) 2A
    • Potential difference between A & B as shown in figure is  (a) 1Volt  (b) 2Volt (c) 3Volt  (d) 4 Volt
    • What is the value of current flowing at point A in above circuit?   (a) 1 Ampere        (b) 2 Ampere   (c) 3 Ampere          (d) 4 Ampere