Light Reflation & Refraction Part 2 MCQ

## Electricity Heating & Chemical Effect

Q. When a charge q flows through a conductor in time t, then current I is given by the reaction:

(A) I=t/q
(B) I=q/t
(C) I=qXt
(D) q=I+t

Q. When 1 coulomb of charge flow through any section of a wire in 1 second, the current flowing through the wire is:

(A) 1 ampere
(B) 1 volt
(C) 1 ohm
(D) 1 N/C

Q. A current of 4 amperes flows through a conductor for 20 minutes. The charge which passes through the conductor is:

(A) 80 coulombs
(B) 3200 coulombs
(C) 4800 coulombs
(D) 480 coulombs

Q. Ohm law deals with the relation between:

(A) charge and potential
(B) current and potential difference
(C) charge and resistance
(D) current and electric intensity

Q. A current of 1 ampere flows through a wire when a potential difference of 1 volt is applied to it.The resistance of the wire is:

(A) 1 ohm cm
(B) 1 watt
(C) 1 volt
(D) 1 ohm

Q. An electric bulb in a train is drawing 0.4-ampere current at 20 volts.the resistance of the buld is:

(A) 20Ω
(B) 50Ω
(C) 40Ω
(D) 8Ω

Q. A current of 25 amperes is equivalent to:

(A) 25 joule/sec
(B) 25 volt/sec
(C) 25 coulomb/sec
(D) 25 watt/sec

Q. Three conductors of resistances r1,r2 and r3 are connected in series, the equivalent resistance R is given by the relation;

(A) R=r1+r2+r3
(B) R=r1r2+r2r3+r3r1
(C) R=1/r1+1/r2+1/r3
(D) 1/R= 1/r1+1/r2+1/r3

Q. Three resistances of 2, 3 and 6 ohms are connected in parallel the total resistance is:

(A) 36Ω
(B) 11Ω
(C) 1Ω
(D) 7Ω

Q. Two wires each resistance r ohms are joined in parallel.Their equivalent resistance will be:

(A) 2r Ω
(B) r/2 Ω
(C) 2/r Ω
(D) zero Ω

Q. Rate of doing work in an electric circuit is called:

(A) power
(B) energy
(C) current
(D) voltage

Q. Which of the following is the unit of electric power?

(A) joule
(B) coulomb
(C) volt
(D) watt

Q. The units of electric power (watts)electric current (ampere) and potential difference (volt)are connected by the relation:

(A) ampere=volt x watt
(B) watt= volt x Ampere
(C) volt=watt x Ampere
(D) watt=volt+ampere

Q. An electric bulb is marked 100watt,  200volts.The current through the bulb is:

(A) 0.5 Ampere
(B) 5 ampere
(C) 2 ampere
(D) 10 ampere

Q. A 100watt 220-volt bulb burns for 10 hours.The electrical energy(no.of units)consumed is equal to:

(A) 0.5kWh
(B) 0.2kWh
(C) 1.0kWh
(D) 1.5kWh

Q. When cells are arranged in parallel:

(A) the current capacity increases
(B) the current capacity decreases
(C) the e.m.f.increases
(D) the e.m.f decreases

Q. A resistor r1 dissipates the power p when connected to a certain generator.If a resistance r2 is put series with r1 the power dissipated by r1;

(A) decreases
(B) increases
(C) remains the same
(D) any of the above depending upon the value of R1 and R2

Q. Appliances based on the heating effect of current work on:

(A) d.c only
(B) a.c only
(C) both a.c and d.c
(D) none of these

Q. An a.c supply may be used directly for all these except for one.Identily the one for which cannot be used;

(A) heating
(B) lighting
(C) transforming voltage
(D) electroplating

Q. One volt is equal to;

(A) 1 joule
(B) 1 newton/coulomb
(C) 1 joule/coulomb
(D) 1 newton/second

Q. A piece of copper and germanium are cooled from room temperature to 80 k.The resistance of:

(A) each of them increases
(B) each of them decreases
(C) copper increases and germanium decreases
(D) copper decreases and germanium increases

Q. A current of 2A passing through a conductor produces 80j of heat in 10 seconds.The resistance of the conductor is:

(A) 4 Ω
(B) 2 Ω
(C) 0.5 Ω
(D) 20 Ω

Q. The current flowing through an electric bulb rated 200 volts 100 watts is:

(A) 0.5 A
(B) 2 A
(C) 100 A
(D) 200 A

Q. A current of 4.8 Amp.is flowing in a conductor.The number of electrons flowing per second through the conductor will be:

(A) 3×1019
(B) 76.8×1020
(C) 7.68×1020
(D) 3×1020

Q. There 2-ohm resistors are connected to form a triangle.The resistance between any two corners is:

(A) 6 Ω
(B) 2 Ω
(C) 3/4 Ω
(D) 4/3 Ω

Q. Two electric bulbs have tungsten filament of the same length.If one of themgives 60 watts and the pther 100 watts,then:

(A) 100 watt bulb has thicker filament
(B) 60 watt bulb has thicker filament
(C) both filament are of the same thicker
(D) it is impossible to get different wattage unless the lengths are different

Q. The resistance of 20 cm long wire is 5 ohm.the wire is stretched to a uniform wire of 40 cm length.The resistance now will be (in ohms.)

(A) 5 Ω
(B) 10 Ω
(C) 20 Ω
(D) 200 Ω

Q. Two resistance are joined in parallel whose resultant is 6/5 ohm. Ohm of the resistance wire is broken and the effective resistance becomes 2 ohms.Then the resistance in ohm of the wire that got broken was:

(A) 3/5Ω
(B) 2Ω
(C) 6/5Ω
(D) 3 Ω

Q. A kilowatt-hour is a unit of:

(A) energy
(B) power
(C) electric charge
(D) electric current

Q. One-kilowatt hour equals:

(A) 36×105 joule
(B) 36×103
(C) 103
(D) 105

Q. Two heater wires of equal length are first connected in series and then in parallel.The ratio of the heat produced in the two cases is:

(A) 2:1
(B) 1:2
(C) 4:1
(D) 1:4

Q. Two electric bulbs is rated 220 volts and 100-watt power consumed by it when operated on 100 volts is:

(A) 50 W
(B) 75 W
(C) 90 W
(D) 25 W

Q. Two electric lamps of 40 watts each are connected in parallel.The power consumed by the combination will be:

(A) 20 watt
(B) 60 watt
(C) 80 watt
(D) 100 watt

Q. Voltmeter is an instrument used for:

(A) potential measurement
(B) current measurement
(C) Electrolysis
(D) charge measurement

Q. A strong battery is to be charged from a d.c supply.Which terminal of the  battery be connected to the positive side of the line?

(A) positive
(B) negative
(C) both positive and negative
(D) first negative and after the lapse of 5 minute positive

Q. A cell of 40 ampere-hour capacity can supply a current of:

(A) 40 ampere for one hour
(B) 1 ampere for 40 hours
(C) 1/2 ampere for 40 hours
(D) 20 ampere for two hours

Q. The instrument which converts sound energy into electric energy is:

(A) loudspeaker
(B) microphone
(C) transformer
(D) electric motor

Q. Electrical energy is transmitted at high voltage to:

(A) reduce losses
(B) convert power
(C) reduce length

Q. The resistance of an ideal ammeter will be:

(A) Zero
(B) infinity
(C) more then zero
(D) less then infinity

Q. The galvanometer is converted to ammeter by:

(A) using shunt of low resistance in parallel
(B) using coil
(C) using pipe
(D) using shunt in series

Q. Which instrument has maximum resistance?

(A) Ammeter
(B) voltmeter
(C) galvanometer
(D) voltaic cell

Q. An electric bulb marked 60W used 5 hours a day.If it is used for 30 days then the electric units consumed 30 days would be:

(A) 10
(B) 3
(C) 6
(D) 9

Q. An electric fan marked 60-watt consumer 3 units for the duration:

(A) 50 hours
(B) 150 hours
(C) 100 hours
(D) 15 hours

Q. An electric bulb marked 100 W and 400V. During consumption the resistance of its filament would be:

(A) 1500 ohm
(B) 1600 ohm
(C) 1000ohm
(D) 2000ohm

Q. Electric bulbs marked 60W and 100V. During consumption the amount of electric current would be:

(A) 0.6 Amp
(B) 6 Amp
(C) 1.6 Amp
(D) 0.06 Amp

Q. The filament of the electric heater is made of:

(A) nichrome mixed metal
(B) iron
(C) aluminium
(D) copper

Q. An electric heater marked 550W is used for 8 hours a day. If the rate of electricity charge is Rs.0.20 per unit then total expenditure would be:

(A) Rs.0.38
(B) Rs.7.70
(C) Rs. 0.88
(D) Rs.188.

Q. Two electric bulbs marked 25W-120V and 100 W-120V are joined in series to the same source of 120V.Which electric bulb will yield more light.

(A) 25W-120V
(B) 100W-120V
(C) both
(D) none of these

Q. In a house six 100 watt electric bulbs are lighted for 4 hours daily.The electric energy consumption,is:

(A) 240 kwh
(B) 24 kwh
(C) 2.4 kWh
(D) 0.24 kwh

Q. An electric heater of 1.5 kW is used for 2 hours daily. The cost of energy consumed in a month or 30 days when the rate of energy is Rs.1.20 per unit is:

(A) Rs.3.60
(B) Rs.10.80
(C) Rs.1080
(D) Rs.108.00

Q. A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio R/R is:

(A) 1/25
(B) 1/5
(C) 5
(D) 25

Q. Which of the following terms not represent electric power in a circuit?

(A) I2R
(B) IR2
(C) VR
(D) V2/R

Q. An electric bulb is rated at 220 V and 100W. When it is operated on 110 V,  the power consumed will be:

(A) 100W
(B) 75W
(C) 50W
(D) 25W

Q. Two conducting wires of the same material and of equal rights and equal diameter are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be:

(A) 1:2
(B) 2:1
(C) 1:4
(D) 4:1