VIZAG MT EE FREE ONLINE TEST 1 ANSWERS KEY & EXPLANATION

VIZAG MT EE FREE ONLINE TEST

1.Total no of questions 20. 2.To marks 20 3.There is no negative marking. 4.Minimum passing marks 30 percentage.

1. If the excitation is critical, the power factor of the alternator is

none of the above
leading power factor
*unity power factor
lagging power factor

the generator neither supplies nor draws any reactive power and operates at unity power factor.

2. Lowest critical frequency is due to pole and it may be present origin or nearer to origin, then it is which type of network?

Any of the above
RL
LC
*RC

In RC network lowest critical frequency is due to pole and it is at origin or nearer to origin depending on the value of the capacitance value and transfer function.

3. Eddy current loss will depends on

*All of the above
Flux density
Frequency
Thickness

eddy current loss will depend upon frequency, flux density and the area of the eddy current loop.

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4. In an SR latch built from NOR gates, which condition is not allowed

*S=1, R=1
S=0, R=1
S=0, R=0
S=1, R=0

At S=0, R=0, Output of the latch becomes Q=0, B_bar=0, which is an unwanted state. also known as indeterminate state.

5. In a single phase induction motor, the starting torque developed is proportional to

1/V
*V²
supply voltage V
1/V²

torque developed is proportional to V².

6. A single phase full bridge inverter can operated in load commutation mode in case load consist of

RLC critically damped.
*RLC underdamped.
RL
RLC overdamped

In this case reading current will flow in circuit and it will became zero so thyristor will be load commutated

7. Magnetic flux has the unit of

Tesla
Ampere turn
Newton
*Weber

The unit of magnetic flux is called Weber in honor of famous scientist Wilhelm Eduard Weber (1804 – 1891). Magnetic flux has also another unit named Maxwell. 1 Maxwell = 10-8 Weber.

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8. Ward-Leonard control is basically a ___________ control method.

Field diverter control.
Armature resistance control.
Field control.
*Armature voltage control.

Ward-Leonard speed control method consists a motor with a constant excitation and applying a variable voltage to its armature to provide the required speed. Hence it is armature voltage control method.

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9. The value of diversity factor is

*greater than 1
1
0
less than 1

Diversity factor is defined as the ratio of sum of individual maximum demand to the station maximum demand. Maximum demand of each consumer does not occur at the same time. They occur at different time of the day. So their sum is always greater than the maximum demand a particular time. Therefore, diversity factor value is more than 1.
10. Which of the following is the analogous quantity for mass element in force-voltage analogy?

all of the above
*inductance
resistance
capacitance

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