Electrical Engineering Quiz 5

1 / 50

Total number of crystal systems is____________?

2 / 50

The power scale of circle diagram of an induction motor can be found from__________?

short-circuit test only

noue of the above

no-load test only

stator resistance test

3 / 50

During discharge, the active material of both the positive and negative plates is changed to___________?

Pb02

PbO

PbS04

4 / 50

Short-circuit test on an induction motor cannot be used to determine___________?

windage losses

power scale of circle diagram

copper losses

transformation ratio

5 / 50

In parallel resonance, the circuit impedance is_________________?

CR/L

L/CR

C/LR

R/LC

6 / 50

In resistance heating highest working temperature is obtained from heating elements made of_____________?

silver

nichrome

nickel copper

silicon carbide

7 / 50

PVC stands for____________?

polyvinyl chloride

positive voltage conductor

pressed and varnished cloth

post varnish conductor

8 / 50

If the load resistance decreases in a Zener regulator, then Zener current ______________?

None of the above

Decreases

Stays the same

Increases

9 / 50

Long distance railways use which of the following ?

200 V D.C.

25 kV three phase A.C.

25 kV single phase A.C.

25 kV two phase A.C.

10 / 50

Mercury is a choice with steam in binary vapour cycle because it has____________?

relatively low vapourisation pressure

higher saturation temperature than other fluids

higher critical temperature and pressure

all above

11 / 50

The maximum efficiency of resistance loaded class A power amplifier is _________________?

50%

30%

25%

12 / 50

If a 6 uF capacitor is charged to 200 V, the charge in coulombs will be____________?

1600 uC

900 uC

800 uC

1200 uC

13 / 50

When an ammeter is inserted in the circuit, the circuit current will _____________?

None of the above

Increase

Decrease

Remain the same

14 / 50

IC = aIE +____________?

ICEO

?IB

ICBO

15 / 50

What will be the magnetic potential difference across the air gap of 2 cm length in magnetic field of 200 AT/m ?

10 AT

2 AT

6 AT

4 AT

16 / 50

In conductors conduction of electricity takes place due to movement of_______________?

negative ions only

positive ions only

positive and negative ions

electrons only

17 / 50

In a series resonant band-pass filter, a lower value of Q results in______________?

a higher resonant frequency

a higher impedance

a smaller bandwidth

a larger bandwidth

18 / 50

When a conductor carries more current on the surface as compared to core, it is due to___________?

unsymmetrical fault

skin effect

corona

permeability variation

19 / 50

The following constitute short-circuit in the armature winding.

Insulation failure between two turns of a coil

All of the above

Two of more turns of the same coil getting grounded

Insulation failure between two commutator bars

20 / 50

An average voltage of 10 V is induced in a 250 turns solenoid as a result of a change in flux which occurs in 0.5 second. The total flux change is____________?

0.02 Wb

20 Wb

0.2 Wb

2 Wb

21 / 50

Copper brushes in D.C. machine are used_____________?

where low voltage and high currents are involved

in none of the above cases

where high voltage and small cur-rents are involved

in both of the above cases

22 / 50

In a rotary converter I2R losses as compared to a D.C. generator of the same size will be___________?

double

three times

less

same

23 / 50

A thyristor string is made of a no. of SCR connected in series and parallel. The string have volume and current of 11 KV and 4 K The voltage and current rating of available SCRs are 1800 V and 1000 For a string efficiency of 90 % let the number of SCRs in series and parallel are a and b respectively. Then the value of a and b will be_____________?

4, 6

7, 5

6, 4

5, 7

24 / 50

capacitors are used for audio frequency and radio frequency coupling and tuning ?

Mica

Air

Ceramic

Plastic film

25 / 50

Which of the following motor has the poorest speed regulation ?

Cumulative compound motor

Series motor

Shunt motor

Differential compound motor

26 / 50

The leakage current across a pn junction is due to________________?

None of the above

Junction capacitance

Majority carriers

Minority carriers

27 / 50

Damping of the Ballistic galvanometer is made small to_______________?

get minimum overshoot

make the system oscillatory

make the system critically damped

get first deflection large

28 / 50

For Parson?s reaction steam turbine, degree of reaction is____________?

60%

50%

100%

75%

29 / 50

In split-phase motor auxiliary winding is of___________?

thick wire placed at the bottom of the slots

thin wire placed at the bottom of the slots

thick wire placed at the top of the slots

thin wire placed at the top of the slots

30 / 50

What will be the collector efficiency of a power amplifier having zero signal power dissipation of 5 watts and a.c. power output of 2 watts ?

80%

50%

40%

20%

31 / 50

What is used to protect a thyristor from high di / dt conditions__________?

Snubber circuit

Fuse.

Voltage clamping device

Inductor

32 / 50

1 volt/meter is same as___________?

1 joule/coulomb

1 meter/coulomb

1 newton meter

1 newton/meter

33 / 50

If the anode current is 800 A, then the amount of current required to turn off the GTO is about____________?

20 A

200 A

600 A

400 A

34 / 50

In a series parallel circuit, any two resistances in the same current path must be in___________?

series with the voltage source

parallel with the voltage source

series with each other

parallel with each other

35 / 50

Insertion of reactance in the rotor circuit_______?

increases starting torque as well as maximum torque

increases starting torque but maxi-mum torque decreases

reduces starting torque as well as maximum torque

increases starting torque but maxi-mum torque remains unchanged

36 / 50

Six resistors are in parallel. The two lowest-value resistors are both 1.2 k?. The total resistance______________?

is greater than 1.2 k?

is less than 600 ?

is less than 6 k?

is less than 1.2 k?

37 / 50

The best indication about the state of charge on a lead-acid battery is given by____________?

output voltage

none of the above

temperature of electrolyte

specific gravity of electrolyte

38 / 50

Parson?s turbine is___________?

simple single wheel, impulse steam turbine

pressure compounded steam turbine

multi wheel reaction steam turbine

simple single wheel reaction steam turbine

39 / 50

During load shedding:

system power factor is changed

some loads are switched off

system frequency is reduced Efficiency is the secondary consideration in

system voltage is reduced

40 / 50

The attraction capacity of electromagnet will increase if the_______________?

flux density increases

flux density decreases

core area increases

core length increases i

41 / 50

Which of the following alternatives will be cheaper ?

Ten motors of 10 H.P. each

Five motors of 20 H.P. each

Four motors of 25 H.P. each

A 100 H.P. A three phase motor

42 / 50

In a shaded pole single-phase motor, the revolving field is produced by the use of_________?

inductor

shading coils

capacitor

resistor

43 / 50

To send 10% of the main current through a moving coil galvanometer of resistance 99 O the shunt required is______________?

9 O

11 O

9 O

100 O

44 / 50

Relative permeability of vacuum is__________?

4n x 10-? H/m

1 H/m

1/4JI

45 / 50

Materials subjected to rapid reversal of magnetism should have______________?

large area oiB-H loop

high co-ercivity and high retentivity

high permeability and low hysteresis loss

high co-ercivity and low density

46 / 50

Volt box is a component to_____________?

compare voltage in a box

none of the above

extend voltage range

measure voltage

47 / 50

All of the following are equivalent to watt except_____________?

amperes/volt

joules/seC.

(amperes) ohm

amperes x volts

48 / 50

The curve between V and I of SCR when anode is positive w.r.t cathode and when anode is negative w.r.t cathode are known as_____________________?

former as reverse characteristics and later as forward characteristics

former as forward characteristics and later as reverse characteristics

both as forward characteristics

both as reverse characteristics

49 / 50

The effects of EMI can be reduced by_____________?

Reducing the efficiency of the coupling path

All of these

Reducing the susceptibility of the receptor

Suppressing emissions

50 / 50

The Q of the crystal is of the order of____________?

100

More than 10,000

1000

Provide Your Information

NameEmailPhone Number

Your score is

The average score is 95%