CHAPTER 14
CURRENT ELECTRICITY
Encircle the most appropriate answer from the following options :
(1) In metals, current is produced only due to the now of
(a) Protons
(b) Electrons
(c) Free electrons
(d) Neutrons
(2) In electrolyte, current is produced due to the now of
(a) Positive charge
(b) Negative charges
(c) Both positive and negative charges
(d) None of these
(3) the he rate of now of electric charge through any cross-sectional area is called
( a) Electrostatics
(b) Electric current
(c) e.m.f
(d) Voltage
(4) The SI unit of electric current is
(a) volt
(b) Farad
(e) Capacitånce
(d) Ampere
(5) The equis alent current of positive charges which flows through a conductor is known as
( a) Electronic current
(b) conventional current
(c) Electrostatic
(d) Ampere
(6) the current due to negative charges and an equivalent current due to positive charges always flow in the
( a ) Opposite direction
(b) Same direction
(c) Perpendicular to each other
(d) None of these
(7) In electricity. we assume that electricity. current is always due to the flow of
(a) Negative charges
(b) Neutral particles
(c) positive charges
(d) Both negative and positive charges
(8) the conventional current of positive charges flow from the point of
(a) Higher potential to a point of lower potential
(b) Lower potential to a point of higher potential
(c) Lower potential to a point of lower potential
(d) Higher potential to a point of higher potential
(9) The current constituted by negative charges flows from a point of
(a) higher potential to a point of a lower potential
( b) lower potential to a point of higher potential
(C) lower potential to a point of’ lower potential
(d) Higher potential to a point To Higher potential
( 10) When we connect a battery across a conductor the energy is provided in charges to the conductor by the
(a) Magnetic field produced in the conductor
(b) Electromagnetic field produced in the conductor
(c) Electric field produced in the conductor
(d) None of the above
(11) Energy is produced to transfer the electrons from positive terminal of the battery to the negative terminal by the
(a) Electrical process
(b) Chemical process
(c) Thernval process
(d) Magnetic process
( 12) The current through a metallic conductor is because of the motion of
(a) Protons
(b) Neutrons
(c) Electrons
(d) Free electrons
(13) In liquids and gases, the current is due to the motion of
(a) Negative charges
(b) Positive charges
(c) Both negative and positive charges
(d) Neutral particles
(14) Free electrons are
(a) Visually bound
(b) Fixed
(c) Loosely bound
(d) Tightly fixed
(15) The direction of conventional current flowing in a circuit is
(a) from negative to positive in the external circuit and from positive to negative within the source of potential difference (battery)
(b) from positive to negative in the external circuit and from negative to positive within the source of P.D.
(c) From positive to negative throughout the circuit.
(d) From negative to positive throughout the circuit.
(16) The direction of the electronic current in the closed circuit is
(a) along the flow of electrons
(b) opposite to the flow of electrons
(c) From positive to negative in the external circuit
(d) along the direction of positive charges.
(17) If a charge ‘Q’ flows through any cross-section of the conductor in time ‘t’ second, the current ‘I ‘ is given by
(a) I = Qt
(b) I = Q/t
(c) I = t/Q
(dl I = Q2/t
(18) One coulomb per second is equal to
(a) One volt
(b) One ampere
(c) One watt
(d) One ohm
(19) Which of the following represents electronic current
(a) ErgC-1
(b) Cs-1
(c) J s-1
(d) DyneS-1
(20) If I ampere current flows charge flow through this in lhour will be
(a) 3600 C
(b)7200C
(c) 1C
(d) 2C
(21) Butteries convert
( a) electrical energy into heat energy
(b) electrical energy into chemical energy
(c) electrical energy into electrical energy
(d) heat energy into chemical energy
(22) The electronic current is due to the flow of
(a) negative charge
(b) positive charge
(c) both (a) and (b)
(d) none of the above
(23) The conventional current Is due to the flow of
(a) negative charge carriers
(b) neutrarcharge
(c) positive charge carriers
(d) both negative and positive charges carriers.
(24) The energy required to move n charge from one point to another in the circuit Is called
(a) e.m.f
(b) Potential difference
(c) Resistance
(d) Volt
(25) Volt is n unit of
(a) Potential difference
(b) e,m.f
(c) Potential difference and emf.
(d) None of these
26). The energy supplied In driving one coulomb of charge round a complete circuit In which the cell ls connected Is called
(a) e.m.f
(b) Potential difference
(c) Resistance
(d) Volt
(27) The Instrument with which we can detect the presence of current In a circuit Is known as
(a) Voltmeter
(b) Ammeter
(c) Galvanometer
(d) Ohm meter
(28) In order to detect the current, galvanometer Is connected
(a) In parallel
(b) in series
(c) May be parallel or in series
(d) A ny where in the circuit
(29) If the needle of galvanometer shows some deflection, it would indicate the
(a) Presence of current
(b) Absence of current
(c) A large current
(d) None of these
(30) A galvanometer is a very
(a) Large instrument
(b) Small instrument
(c)Insensitive instrument
(d) Sensitive instrument
(31) A resistance which is connected with the galvanometer in order to convert it into ammeter should have
(a) High resistance
(b) Very high resistance
(c) Low resistance
(d) Very low resistance
(32) The resistance of an ammeter should be
(a) Height
(b) Very high
(c) Low
(d) Very low
(33) In order to measure the current in a circuit, ammeter should be connected
(a) Parallel 10 battery
(b) In series ill the circuit
(c) May be parallel or in series
(d) N one of these
(34) When ammeter is connected in the circuit, the positive terminal of ammeter should be connected with the
(a) Negative terminal of the battery
(b) Positive terminal of the battery
(c) Any terminal of the battery
(d) None of these
(35) The potential difference can be directly measured by the instrument known as
(a) Ammeter
(b) potentiometer
(c) voltmeter
(d) Ohm meter
(36) The series resistance„ which is _ connected galvanometer to ( it Into voltmeter usually has value in
(a) Ohms
(b) several hundred Ohms
(c) several thousand Ohms
(d) Hundred thousand Ohms
(37). Voltmeter is always connected in a circuit in the
(a) series
(b) parallel
(c) May be in series or parallel
(d) None of these
(38) A good voltmeter is that which draws
(a) No current
(b) Single current
(c) Large current
(d) Very large current
(39) The relation V = IR represents
(a) Ampere’s law
(b) Coulomb’s law
(c) Faraday’s law
(d) ohm’s law
(40) Ohm’s law is applicable to
(a) Liquids only
(b) Gases only
(c) Liquid conductors only
(d) Metallic eonduetofs only
(41) Ohm the unit of
(a) Current
(b) Capacitance
(c) Electric intensity
(d) Resistance
(42) Ohm can be defined as
(a) Volt / Coulomb VC– 1
(b) volt / Ampere VA – 1
(c) Ampere / volt CV– 1
(d) ampere / volt AV– 1
(43) Circuit breaker works on the principle of:
(a) Electric current
(b) Joule’s law
(c) Electromagnetism
(d) None of them
(44) Thermistor is
(a) A heat sensitive resistor
(b) potential divider
(c) constant resistor
(d) An ordinary resistor
(45) The graphical representation of Ohm’s law is
(a) Hyperbola
(b) Ellipse
(c) Parabola
(d) Straight line
(46) The value of current passing through a conductor is directly proportional to the
(a) Resistance
(b) Capacitance
(c) Potential
(d) None of these
(47) The property of a substance which opposes the flow of current through it is called
(a) Conductivity
(b) Capacitance
(c) Resistance
(d) Conduction
(48) If a potential of 220V is applied across a conductor and a current of 2A through it. What would be the resistance of the conductor?
(a) 210 ☊
(b) 440 ☊
(c) 880 ☊
(d) 110 ohm
(49) The resistance of a meter cube of the substance is called
(a) conductivity
(b) penni!tivity
(c) resistivity
(d) susceptibility
(50). At a particular temperature, the resistance of a wire will directly proportional to its
(a) Length
(b) Area of cross-section
(c) Shape
(d) Colour
(51) At a particular temperature, the resistance of a wire will inversely proportional to its
(a) Length
(b) Area cross-section
(c) Temperature
(d) Colour
(52) If we increase the length of a “ire tb four times of its original length, what will tie its resistance?
(a) The same
(b) Double
(c) Four times
(d) Eight Innes
(53) If we increase the cross-sectional area of the wire to double of its original area it resistance will become
(a) The same
(b) Halved
(c) One fourth
(d) Doubled
(54) Safety device used in place of fuse is:
(a) Socket
(b) Earth wire
(c) Plug
(d) Circuit breaker
(55) A small wire connected in series with the live wire is called:
(a) Neutral wire
(b) Earth wire
(c) Fuse
(d) Circuit breaker