Download 6. All meters used for measuring current, voltage, and - DIV-A

MCQ – Basic Electrical – Set I
1. The ratio of voltage and electric current in a closed circuit
remains constant
 varies
 increases
 falls
2. The curve representing ohm’s law is


sine function

Linear
A parabola
 a hyperbola
3. The resistance of a conductor having length l area of cross section a and resistivity ρ is
given as:




ρa/l
ρl/a
ρla
l/ρa
4. The resistance of wire varies inversely as

area of cross section
 length
 resistivity
 temperature
5. Which of the following quantities are same in all parts of a series circuit?

voltage
 power
 current
 resistance
6.Which of the following statements is false in case of a series circuit?


the voltage drop across each resister is same
the current flowing through each resistor is the same
 applied voltage is equal to the sum of voltage drops across individual resistors
 resistors are additive
7. A resistance of 30 Ω is connected across 240v supply. If a resistance R Ω is connected
in parallel with 30Ω resistor across the same supply, the current drawn becomes triple
of original one. The unknown resistor R is


15Ω
10Ω
5Ω

30Ω


8. Three resistors, each of R ohms, are connected to form a triangle. The resistance
between any two terminals will be:
2/3 R
 3/2R
 R
 3R
9. Which of the following is not correct?

P=V/R^2
 P=VI
 I=√(P/R)
 V=√PR
10. A 100W bulb is connected in series with a room heater. If now 100W bulb is replaced
by a 40w bulb, the heater output will :


increase

decrease
Remain the same

MCQ – Basic Electrical – Set II
1. The voltage applied across an electric iron is halved. The power consumption of the
iron will be:

one-half
three-fourth
 one-fourth
 1/√2times
2. Resistance of 200w,250v lamp will be

625 Ω
 1250Ω
 312.5Ω
 31.25Ω
3. Two heaters rated at 1000w, 250v each are connected in series across a 250v, 50Hz ac

supply. The total power drawn from the supply will be:
1000w
 500w
 250w
 2000w
4. A 200w, 100v lamp is to be operated on 250v supply. The additional resistance
required to be connected in series will be:

125Ω
 50Ω
 75Ω
 25Ω
5. Kirchoff’s laws are valid for




linear circuits only
passive time invariant circuits
non-linear circuits only
both linear and non-linear circuits
6. KCL is applicable only to

electric circuits
 electronic circuits
 junctions in a network
 closed loop in a network
7. KVL is concerned with

IR drop
 battery emf
 junction node
 both a and b
8. A wye arrangement of resistances has each resistance of 3Ω, the equivalent delta
arrangement will have each resistance of values.


9Ω
6Ω
3Ω

1Ω


9. If Q.8 resistor are connected in delta arrangement then the equivalent wye will be 1Ω.
10. A battery is connected to a resistance causing a current of 0.5A in the circuit. The
current drops to 0.4 when an additional resistance of 5Ω is connected in series . The
current will drop to 0.2A when the resistance is further increased by




10Ω
15Ω
25Ω
40Ω
MCQ – Basic Electrical – Set III
1. Cells are connected in series in order to increase the




current capacity
life of the cells
voltage rating
terminal voltage
2. Cells are connected in parallel in order to increase



life of the cells
efficiency
current capacity
voltage rating
3. When two cells are connected in parallel , it should ensure that have

identical internal resistances
 equal emfs
 same ampere hour capacity
4.The capacity of a battery is expressed in

amperes
 amperes-hour
 watts
 watt-hour
5. A series resonant circuit implies

zero pf and maximum current
 unity pf and maximum current
 unity pf and minimum current
 zero pf and minimum current
6. which one is classified as integrating instrument?



D’arsonval galvanometer
Ampere-hour meter
ohm-meter
 ammeter
7. Which of the following types of instrument is an integrating instrument?

power factor meter
 energy meter
 watt meter

frequency meter
8. Voltmeter should be of very high resistance so that

its range is high
 its accuracy is high
 it may draw current minimum possible
 its sensitivity is high
9. If a voltmeter is connected like a ammeter in series with a load


the measurement reading will be too high
almost no current will flow in the circuit
 the meter will burn out
 an inadmissably high current will flow
10. A multirange instrument (ammeter or voltmeter) has





multiple shunt or series resistances inside the meter
variable coil turns
multi -coil arrangement
any of the above
MCQ – Basic Electrical – Set IV
1. Measuring range of voltmeter can be extended by using
high shunt resistance
 high series resistance
 low shunt resistance
 low series resistance
2. The function of a shunt in an ammeter is to


increase the instrument resistance
bypass the current
 reduce the voltage drop across the instrument coil
 increase the current flowing through the instrument coil
3. A moving instrument has a resistance of 0.6Ω and a full-scale deflection current of
0.1A. To convert it into an ammeter 0-15A range, the resistance of shunt should be




0.6Ω
0.06Ω
0.1Ω
0.004Ω
4. High ac voltage are usually measured with





magnetic voltmeter
inductive voltmeter
potential transformer with voltmeter
current transformers and voltmeter
5. Which instrument has lowest resistance?
ammeter
 voltmeter
 frequency meter

meggar
6. All meters used for measuring current, voltage, and resistance are basically


voltmeter
ammeter

multimeter

none of the above
7. Which of the following is used to measure the resistance of an electrical installation?

multimeter
 ammeter and voltmeter
 maxwell’s bridge
 meggar
8. Meggar is an instrument used for measuring

high resistance and insulation resistance
 medium resistance
 low resistance
 leakage current
9. Which of the following statement associated with purely resistive circuits is correct?



PF is unity
power consumed is zero
heat produced is zero
 PF is zero
10. A leading power factor implies





current leads the voltage
current lags behind the voltage
voltage leads the current
none of the above
MCQ – Basic Electrical – Set V
1. A series resonant circuit implies
zero PF and maximum current
 unity PF and maximum current
 unity PF and minimum current
 zero PF and maximum current
2. DC generator works on the principle f


fleming’s lefthand rule

Fleming’s righthand rule
lenz’s law
 none of the above
3. EMF induced in each conductor of a dc machine is





an alternating emf
a direct emf
pulsating emf
emf of random waveform
4. In large dc generators, the magnetic field is produced by
permanent magnet
 electromagnet
 either a or b
 none of the above
5. The emf generated y a dc generator may be increased by increasing


speed of rotation
excitation
 armature length
 either a or b
6. If we increase field current of a dc generator, its emf output



increases indefinitely
increases till the winding burns
increases till the magnetic saturation takes place
 first increases and then reducing
7. The terminal voltage of a dc shunt generator on loading

increases slightly
 decreases slightly
 decrease sharply
 remains constant
8. The transformer action requires a


constant magnetic flux
increasing magnetic flux
 alternating magnetic flux
 alternating electric flux
9. The induced emf in a transformer depends on




frequency
number of turns
maximum value of flux
all of the above
10. The flux in transformer core





increases with load
decreases with load
remains constant irrespective of load
none of the above
MCQ – Basic Electrical – Set VI
1. Open circuit test in a transformer is performed with




rated transformer voltage
rated transformer current
direct current
high frequency supply
2. In performing the short circuit test on a transformer
high voltage side is usually short circuited
 low voltage side is usually short circuited
 any side is usually short circuited
 none of the above
3. In a transformer





both open and short circuit tests are performed on LV side
Open circuit test is conducted in HV side and short circuit test on LV side
Open circuit test is performed on LV side and short circuit test on HV side
both Open and short circuit tests are performed on HV side
4. Power factor of a ac circuit is defined as
PF=cosθ
 PF=R/|z|
 PF=P(real)/P(app)
 all of the above
5. Power factor PF is


PF α 1/I
PF α I
 PF α I^2
 PF α 1/I^2
6. A transmission as well as distribution system of electric power is known as good if





High value of voltage regulation and efficiency
low value of voltage regulation and high value of efficiency
Good power factor and lower voltage regulation
none of the above
7. Charcoal, common salt are used in earthing due to following reasons:
They increases the conductivity of the soil
 They increases the contact area of the earth
 They maintains moisture and increase earth resistance
 none of the above
8. Voltage source has

smaller resistance than load R
 Higher internal resistance than load R
 Internal resistance is not present i.e zero in all cases
 very small internal resistance
9. Material subjected to rapid reversal of magnetism should have





high permeability and low hysteresis loss
Large B-H loop area
large coercivity and high retentivity
low permeability and large coercivity
10. Area of hysteresis loop represents
copper loss
 eddy current loss
 hysteresis loop
11. Silicon content in steel reduces


hysteresis loop
eddy current loss

copper loss
