R.K. Rajput SET-1

(1):-The flow of current in solid is due to
(a) electrons
(b) electrons and ions
(c) atoms
(d) nucleus

(2):-The resistance of human body is around
(a) 5 ohms
(b) 25 ohms
(c) 250 ohms
(d) 1000 ohms

(3):-The draft velocity of electrons is
(a) very small as compare to speed of light
(b) equal to speed of light
(c) almost equal to speed of light
(d) greater than speed of light

(4):-One commercial unit of energy equals
(a) 500 watts-second
(b) one watt-hour
(c) one killowatt-hour
(d) ten killowatt hour

(5):-One coulomb charge equals the charge on
(a) 6.24×10¹² electrons
(b) 6.24×10¹⁴ electrons
(c) 6.24×10¹⁶ electrons
(d) 6.24×10¹⁸ electrons

(6):-The electrical energy required to heat a bucket of water to a certain temprature is 4 killowatt-hour. if the heat losses are 20%, the energy input is
(a) 2 kwh
(b) 3.2 kwh
(c) 5 kwh
(d) 6 kwh

(7):-In gases the flow of current is due to
(a) electrons only
(b) possitive ions only
(c) electrons and possitive ions
(d) electrons, possitive ions and negative ions

(8):-The maximum current rating for a 10 k-ohm, 0.5W resistor is
(a) 0.707 mA
(b) 7.07 mA
(c) 14.14 mA
(d) 28.28 mA

(9):-An electrical lamp consumes 100W of power.If the supply voltage is 220V the energy consumed in 30 minutes is
(a) 0.005kWh
(b) 0.05kWh
(c) 0.5kWh
(d) 5kWh

(10):-The S.I. unit of power is
(a) henry
(b) coulomb
(c) watt
(d) watt-hour

(11):-Electric pressure is also called
(a) resistance
(b) power
(c) voltage
(d) energy

(12):-The substances which have a large number of electrons and offer a low resistance are called
(a) insulators
(b) inductors
(c) semi-conductors
(d) conductors

(13):-Out of the following which is not a poor conductor?
(a) cast iron
(b) copper
(c) corbon
(d) tungsten

(14):-Out of the following which is an insulating material?
(a) copper
(b) gold
(c) silver
(d) paper

(15):-The property of a conductor due to which it passes current is called
(a) resistance
(b) reluctance
(c) conductance
(d) inductance

(16):-Condutance is reciprocal of
(a) resistance
(b) inductance
(c) reluctance
(d) capacitance

(17):-The resistance of a cunductor varies inversely as
(a) length
(b) area of cross-section
(c) temperature
(d) resistivity

(18):-With rise in temperature the resistance of pure metals
(a) increases
(b) decreases
(c) first increases and then decreases
(d) remains constant

(19):-With rise in temperature the resistance of semi-conductors
(a) decreases
(b) increases
(c) first increases and then decreases
(d) remains constant

(20):-The resistance of a copper wire 200 m long is 21 ohm.If its thickness(diameter) is 0.44 mm, its specific resistance is around
(a) 1.0×10^-8 ohm-m
(b) 1.4×10^-8 ohm-m
(c) 1.6×10^-8 ohm-m
(d) 1.8×10^-8 ohm-m

(21):-Three resistance of 10 ohms,15 ohms and 30 ohms are connected in parallel. The total resistance of the combination is
(a) 5ohms
(b) 10 ohms
(c) 15 ohms
(d) 55 ohms

(22):-The equivalent resistance of a series-parallel circuit shown in fig. 1.7 is
(a) 8 ohms
(b) 10 ohms
(c) 12 ohms
(d) 16 ohms

(23):-The resistance of two wires is 25 ohms when connected in series and 6 ohms when joined in parellel. The resistace of each wire is
(a) 10 ohms,15 ohms
(b) 20 ohms,30 ohms
(c) 5 ohms,10 ohms
(d) 10 ohms,20 ohms

(24):-The equivalent resistance of the circuit shown in fig.1.8 is
(a) 6 ohms
(b) 8 ohms
(c) 14ohms
(d) 20 ohms

(25):-An instruments which detects electric current is known is
(a) voltmeter
(b) rheostat
(c) wattmeter
(d) galvanometer

(26):-The equivalent resistance of the circuit shown in fig. 1.9 is
(a) 15 ohms
(b) 20 ohms
(c) 25 ohms
(d) 30 ohms

(27):-In a circuit a 33ohm resistor carries a current of 2A. The voltage across the resistor is
(a) 33V
(b) 66V
(c) 80V
(d) 132V

(28):-A light bulb draws 300mA when the voltage across it is 240V. The resistance of the light bulb is
(a) 400 ohms
(b) 600 ohms
(c) 800 ohms
(d) 1000 ohms

(29):-The resistance of a parallel circuit consisting of two branches is 12 ohms. If the resistance of one branch is 18 ohms,what is the resistance of the other?
(a) 18 ohms
(b) 36 ohms
(c) 48 ohms
(d) 64 ohms

(30):-Four wire of same material, the same cross-section area and the same lenght when connected in parallel give a resistance of 0.25 ohms. If the same four wires connected is series the effective resistance will be
(a) 1 ohm
(b) 2 ohms
(c) 3 ohms
(d) 4 ohms

(31):-A current of 16 A devided between two branches in parallel of resistance 8 ohms and 12 ohms respectively. The current in each branch is
(a) 6.4 A,6.9 A
(b) 6.4 A,9.6 A
(c) 4.6A,6.9A
(d) 4.6A,9.6A

(32):-Current velocity through a copper conductor is
(a) The same as propagation velocity of electric energy
(b) independent of current strength
(c) of the order of a few microsecond/meter
(d) nearly 3×10⁸ m/sec

(33):-Which of the following material has nearly zero temperature co-efficient of resistance?
(a) manganin
(b) porcelain
(c) corbon
(d) copper

(34):-You have to replace 1500ohms resistor in radio. You have no 1500ohms resistor but have several 1000ohms once which you would connect
(a) two in parallel
(b) two in parallel and one in series
(c) three in parallel
(d) three in series

(35):-Two resistors are said to be connected in series when
(a) same current posses in turn through both
(b) both carry the same value of current
(c) total current equals the sum of branch current
(d) sum of IR drops equals the applied e.m.f.

(36):-Which of the following statement is true both for a series and a parallel D.C. curcuit?
(a) elements have individual
(b) currents are additive
(c) voltages are additive
(d) power are additive

(37):-Whatever the battery voltage in fig. 1.10, it is certain that smallest current will flow in the resistance of .....ohms
(a) 250
(b) 150
(c) 50
(d) 100

(38):-Which of the following materials has a negative temperature co-efficient of resistance?
(a) copper
(b) aluminium
(c) corbon
(d) brass

(39):-Ohm's law is not applicable to
(a) vacuum tubes
(b) corbon resistors
(c) high voltage circuits
(d) curcuits with low current densities

(40):-Which is the best conductor of electricity
(a) iron
(b) silver
(c) copper
(d) corbon

(41):-For which of the following 'ampere second'could be the unit?
(a) reluctance
(b) charge
(c) power
(d) energy

(42):-All of the following are equivalent to watt except
(a) (amperes)² ohm
(b) joules/sec
(c) amperes×volts
(d) amperes/volt

(43):-a resistance having rating 10ohms, 10W is likely to be a
(a) metallic resistor
(b) corbon resistor
(c) wire wound resistor
(d) variable resistor

(44):-Which one of the following does not have negative temperature co-efficient?
(a) aluminium
(b) paper
(c) rubber
(d) mica

(45):-Varistors are
(a) insulators
(b) non-linear resistors
(c) corbon resistors
(d) resistors with zero temperature co-efficient

(46):-Insulating materials have the fuction of
(a) preventing a short circuit between conducting wires
(b) preventing an open circuit between the voltage source and the load
(c) conducting very large currents
(d) storing very high current

(47):-The rating of a fuse wire is always expressed in
(a) ampere-hours
(b) ampere-volts
(c) kWh
(d) amperes

(48):-The minimum charge on an ion is
(a) equal to the atomic number of the atom
(b) equal to the charge of an electron
(c) equal to the charge of the number of electrons in an atom
(d) zero

(49):-In a series circuit with unequal resistances
(a) the highest resistance has the most of the current through it
(b) the lowest resistance has the highest voltage drop
(c) the lowest resistance has the highest current
(d) the highest resistance has the highest voltage drop

(50):-The filament of an electric bulb is made of
(a) corbon
(b) aluminium
(c) tungsten
(d) nickel

(51):-A 3ohms resistor having 2A current will dissipate the power of
(a) 2 watts
(b) 4 watts
(c) 6 watts
(d) 8 watts

(52):-Which of the following statement is true?
(a) a galvanometer with low resistance in parallel is a voltmeter
(b) a galvanometer with high resistance in parallel is a voltmeter
(c) a galvanometer with low resistance in series is an ammeter
(d) a galvanometer with high resistance in series is an atmmeter

(53):-The resistance of a few meter of wire conductor in closed electrical circuit is
(a) practically zero
(b) low
(c) high
(d) very high

(54):-If a parallel circuit is opened in the main line, the current
(a) increases in the branch of the lowest resistance
(b) increases in each branch
(c) is zero in all branches
(d) is zero in the highest resistive branch

(55):-If a wire conductor of 0.2 ohm resistance is doubled in lenght, its resistance becomes
(a) 0.4ohms
(b) 0.6ohms
(c) 0.8ohms
(d) 1.0ohms

(56):-Tree 60W bulbes are in parallel across the 60V power line. If one bulb burns open
(a) there will be heavy current in the main line
(b) rest of the two bulbs will not light
(c) all the three bulbs will light
(d) the other two bulbs will light

(57):-The four bulbs of 40W each each are connected in series with a battery across them, which of the following statement is true?
(a) the current through each bulb is same
(b) the voltage across each bulb is not same
(c) the power dissipation in each bulb is not same
(d) none of the above

(58):-Two resistance R1 and R2 are connected in series across the voltage source where R2>R1. the largest drop will be across
(a) R2
(b) R1
(c) either R1 or R2
(d) none of them

(59):-What will be energy used by the battery if the battery has to drive 6.28*10^18 electrons with potential difference of 20V across the terminal?
(a) 5 joules
(b) joules
(c) 15 joules
(d) 20 joules

(60):-A closed switch has a resistance of
(a) zero
(b) About 50ohms
(c) about 500 ohms
(d) infinity

(61):-The hot resistance of the bulb's filament is higher than its cold resistsnce becouse the temperature co-efficient of the filament is
(a) zero
(b) negative
(c) positive
(d)about 2 ohms per degree

(62):-Heat in a conductor is produced on the passage of electric current due to
(a) reactance
(b) capicitance
(c) impedence
(d) resistance

(63):-The insulation on a current carrying conductor is provided
(a) to prevent leackage of current
(b) to prevent shock
(c) both of above factors
(d) none of the above factors

(64):-The th ickness of insulation provided on the conductor depends on
(a) the magnitude of voltage on the conductor
(b) the magnituude of current flowing throw it
(c) both (a) and (b)
(d) none of the above

(65):-Which of the following quantities remain the same in all part of a series circuit?
(a) voltage
(b) current
(c) power
(d) resistance

(66):-In the circuit shwon in fig. 1.11 if the resistance of battery is zero and the resistance R is gradually increased , voltmeter reading will
(a) decrease
(b) increase
(c) first increase and then decrease
(d) remain same

(67):-In the circuit shown in fig. 1.11 if the battery has infinite resistance , voltmeter reading will
(a) increase
(b) decrease
(c) first increase amd then decrease
(d) remain same

(68):-A 40W bulb is connected in series with a room heater. If now 40W bulb is replaced by 100W bulb, the heter output will
(a) decrease
(b) incease
(c) remain same
(d) heater will burn out

(69):-A 500W 220V bulb is supplied with 110V. Power consumption by thr bulb will be
(a) slightly less than 125W
(b) slightly greater than 125W
(c) exactly 125W
(d) 250W

(70):-In in electric kettle water boils in 10 minutes. It is required to boil the boiler in 15 minutes, ussing same supply mains
(a) the length of heating element should be decreased
(b) the length of heating element should be increased
(c) the length of heating element has no effect on heating if water
(d) none of the above

(71):-An electric filament bukb can be worked from
(a) DC supply only
(b) AC supply only
(c) battey supply only
(d) all above

(72):-Resistance of a tungusten lamp ... as aplied voltage increase
(a) decreases
(b) increases
(c) remains same
(d) none of the above

(73):-electric current passing throw the circuit produces
(a) magnetic effect
(b) luminous effect
(c) thermal effect
(d) all of the effects
(e)

(74):-Resistance of a always decreases if
(a) temperature of material is decreased
(b) temperature of material is increased
(c) number of free electrons available becomes more
(d) none of the above is correct

(75):-If the efficiency of a machine is to high, What should be low?
(a) input power
(b) losses
(c) true component of power
(d) kWh consumed
(e) ratio of output to input

(76):-When electric current posses throw a metallic conductor, Its temperature rises. this is due to
(a) collision between conduction electrons and atoms
(b) the release of conduction electrons from parent atoms
(c) mutual collisions between metal atoms
(d) mutual collision between conducting electrons

(77):-Two bulb of 500W and 200W rated at 250V will resistance ratio as
(a) 4:25
(b) 25:4
(c) 2:5
(d) 5:2

(78):-a gass rod when rubbed with silk clothe is charged because
(a) it takes in proton
(b) its atoms are removed
(c) it give away electrons
(d) it give away positve charge

(79):-Whwther circuit may be AC or DC one, following is most effective in reducing the magnitude of the current.
(a) reactor
(b) capacitor
(c) inductor
(d) resistor

(80):-It becomes more difficult to remove
(a) any electrons from the orbit
(b) first electron from the orbit
(c) second electron from the orbit
(d) third electron from the orbit

(81):-When one leg of parallel circuit is opened out the total current will
(a) reduce
(b) increase
(c) decrease
(d) become zero

(82):-In a lamp load when more than one lamp are switched on the total resistance of the load
(a) increases
(b) decreases
(c) remains same
(d) none of the above

(83):-Two lamps 100W and 40W are connected in series across 230V(AC). Which of the following statement is correct?
(a) 100W lamp will glow brighter
(b) 40W lamp will glow brighter
(c) both lamp will glow equqlly bright
(d) 40W lamp will fuse

(84):-Resistance of 220V, 100W lamp will be
(a) 4.84ohm
(b) 48.4ohm
(c) 484ohm
(d) 4840ohm

(85):-On the case of dirrect current
(a) magnitude and direction of current remains constant
(b) magnitude and direction of current change with time
(c) magnitude of current change with time
(d) magnitude of current remains constant

(86):-When elecrtic current passes throw a bucket full of water, lot of bubbling is observed . this suggested that the type of supply is
(a) AC
(b) DC
(c) any of the above
(d) none of the above

(87):-Resistance of corbon filament lamp...as the applied voltage increases.
(a) increases
(b) decreases
(c) remain same
(d) none of the above

(88):-Bulbs in street lighting are all connected in
(a) parallel
(b) series
(c) series-parallel
(d) end-to-end

(89):-For testing appliances, the wattage of lamp should be
(a) very low
(b) low
(c) high
(d) any value

(90):-switchong of a lamp in house produces noise in the radio. This is because switching operation produces
(a) arc across seperating contacts
(b) mechanical noise of high intensity
(c) both mechanical noise and arc between contacts
(d) none of the above

(91):-Sparking occurs when a load is switched of because the circuit has high
(a) resistance
(b) inductance
(c) capacitance
(d) impedence

(92):-Copper wire of cetain length and resistance is drawn out to three times its length without change in valume, the new resistance of wire becomes
(a) 1/9 times
(b) 3 times
(c) 9 times
(d) unchanged

(93):-When reistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will
(a) decrease
(b) increase
(c) remain constant
(d) none of the above

(94):-A field of force can exist between
(a) two molecules
(b) two ions
(c) two atoms
(d) two metal particles

(95):-A substance whose molecules consist dissimilar atoms is called
(a) semi-conductor
(b) super-conductor
(c) compound
(d) insulator

(96):-1 microvolt is
(a) 1×10^-3 V
(b) 1×10^-4 V
(c) 1×10^-5 V
(d) 1×10^-6 V

(97):-Which of the following could be the value of resitivity of copper?
(a) 1.72×10^-4 ohm-meter
(b) 1.72×10^-5 ohm-meter
(c) 1.72×10^-6 ohm-meter
(d) 1.72×10^-8 ohm-meter

(98):-Intenatiobnal ohm is defined in terms of the resitsnce of
(a) a column of murcury
(b) a cube of corbon
(c) a cube of copper
(d) the unit length of wire

(99):-Three identical resistor are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be
(a) 9 times
(b) 1/9 times
(c) 1/3 times
(d) 3 times

(100):-Which of the relation is incorrect?
(a) P=VI
(b) P=(I)²×R
(c) P=V/R²
(d) P=V²/R

(101):-Which method can be used for absolute mesurement of resistance?
(a) Lorentz method
(b) Releigh method
(c) ohm's law method
(d) wheatstone bridge

(102):-The equivalent resistance between L and M of the circuit shown in fig. is
(a) 10ohm
(b) 30ohm
(c) 50ohm
(d) 70ohm

(103):-Three 6 ohm resostor are connected to frm a tringle. What is the resistance between any two corners?
(a) 3/2ohm
(b) 6ohm
(c) 4ohm
(d) 8/3ohm

(104):-ohm's law is not applicable to
(a) semi-conductor
(b) D.C. circuit
(c) small resistors
(d) high currents

(105):-Specific resistance of of a substance is measured in
(a) ohm/m
(b) ohm/m²
(c) ohm-m
(d) m/ohm

(106):-Two copper conductors have equal length, The cross-section area of one is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40ohms the reisistance of other coductor will be
(a) 160ohms
(b) 80ohms
(c) 20ohms
(d) 10ohms

(107):-A nicrome wire used as a heater coil has a resistance of 2ohm/m. For a heater of 1kW at200V, the length of wire required will be
(a) 80m
(b) 60m
(c) 40m
(d) 20m

(108):-Temperature co-efficient of resistence is expressed in terms of
(a) ohms/c
(b) mhos/ohm-c
(c) ohms/ohm-c
(d) mho/c

(109):-Which of the following materials has the least resistivity?
(a) zinc
(b) lead
(c) mercury
(d) copper

(110):-According to the fuse law, the current carrying capacity varies as
(a) 1/(diameter)²
(b) 1/(diameter)
(c) diameter
(d) (diameter)^3/2

(111):-Which of the following lamps will have least resistance at room temperature?
(a) 25W, 220V
(b) 100W, 220V
(c) 200W, 220V
(d) 60W, 220V

(112):-Which resistor will be phisically larger in size?
(a) 100ohm, 10W
(b) 10ohm, 50W
(c) 1Mohm, 1/2W
(d) 1k-ohm, 1W

(113):-When current flow through heater coil it glows but supply wire does not glow because
(a) current through supply line flow at slower speed
(b) supply wiring is covered with insulation layer
(c) resistance of heater coil is more than the supply wire
(d) supply wires are made of superior material

(114):-The condition for the validity under ohm's law is that
(a) resistance must be uniform
(b) current should be proportional to the size of resistance
(c) resistance must be wire wound type
(d) temperature at positive end should be more than the temperature at negative end

(115):-Which of the following statement is correct?
(a) a semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator
(b) a semi-conductor is a material which has conductivity having average value of conductivity of metal and insulator
(c) a semi-conductor is one which conducts only half of the applied voltage
(d) a semi-conductor is a material made of alternate layers of conducting material and insulator

(116):-A rheostat differs from potentiometer in the respect that it
(a) has lower wattage rating
(b) has higher wattage rating
(c) has large number of turns
(d) offers large number of tappings

(117):-The weight of aluminium conductor as compared to a copper conductor of identical cross-sectio, for the same electrical resistance, is
(a) 50%
(b) 60%
(c) 100%
(d) 150%

(118):-An open resistor, when checked with ohm-meter reads
(a) zero
(b) infinite
(c) high but within tolerance
(d) low but not zero

(119):-...are the materials having electrical conductivity much less than most of the metals but much greater than that of tipical insulators.
(a) varistor
(b) thermistor
(c) semi-conductors
(d) variable resistor

(120):-All good conductors have high
(a) conductance
(b) resistance
(c) reluctance
(d) thermal conductivity

(121):-Voltage dependent resistor are usually made from
(a) charcoal
(b) silicon carbide
(c) nichrome
(d) graphite

(122):-Voltage dependent resistors are used
(a) for inductive circuit
(b) to supress surges
(c) as heating elements
(d) as current stabilizer

(123):-The ratio of mass of proton to that of electrons is nearly
(a) 1/1840
(b) 1840
(c) 30
(d) 4

(124):-The number of electrons on the outermost orbit of corbon atom is
(a) 3
(b) 4
(c) 6
(d) 7

(125):-When three resistance connected in parallel, if each dissipiates 20W the total power supplied by the voltage source equals
(a) 10W
(b) 20W
(c) 40W
(d) 60W

(126):-three conductance in parallel jhave the values G1=2000micro-mho, G2=3000micro-mho and G3=4000micromho. The total conductance will be
(a) 6000micro-mho
(b) 7000micro-mho
(c) 9000micro-mho
(d) 10000micro-mho

(127):-A thermistor has
(a) positive temperature co-efficient
(b) negative temperature co-efficient
(c) zero temperature co-efficient
(d) variable temperature co-efficient

(128):-If I, R and t are the current, resistance and time respectivily, then according to joul's law heat produced will be proportional to
(a) I²Rt
(b) I²Rt²
(c) I²R²t
(d) I²R²t²

(129):-Nichrome wire is an alloy of
(a) lead and zinc
(b) chromium and vanadium
(c) nickel and chromium
(d) copper and silver

(130):-When a voltage of 1V is applied, a circuit allows 1micro-A current to flow through it, The conductance of thr circuit is
(a) 1micro-mho
(b) 10⁶ mho
(c) 1milli-mho
(d) none of the above

(131):-which of the following can have negative temperature co-efficient?
(a) compounds of silver
(b) liquid metals
(c) metallic alloys
(d) electrolytes

(132):-Conductance:mho::
(a) resistance:ohm
(b) capacitance:henry
(c) inductance:farad
(d) lumen:steradian

(133):-1 angstrom is equal to
(a) 10^-8 mm
(b) 10^-6 cm
(c) 10^-10 m
(d) 10^-14 m

(134):-One newten meter is same as
(a) one watt
(b) one joule
(c) five joules
(d) one joule second