TasDia Network
TasDia Network

MCQs 1: The stator of split phase induction motor has two windings, main winding and auxiliary winding. These windings are displaced in space by

30 electrical degrees 90 electrical degrees 120 electrical degrees 180 electrical degrees
Answer Explanation

MCQs 2: The flux under the unshaded pole of shaded pole induction motor

Is in equal phase of flux under the shaded pole Lags the flux under the shaded pole Leads the flux under the shaded pole None of these
Answer Explanation

MCQs 3: A two phase servomotor is commonly used in feedback control system to drive the loads and as sensors to measure

Speed of controlled element Position of controlled element Both (a) and (b) None of these
Answer Explanation

MCQs 4: For moment of inertia to be small in two phase servomotor, the ratio of rotor diameter to its length should be

Equal to 1 small large All of these
Answer Explanation

MCQs 5: A load of 110kW at 0.8 power factor is to be shared by two single phase transformer with equal turns have impedances equal to (0.4 + j 0.2) and (0.6 + j 0.8) with respect to secondary. How will they share the load if they are operating in parallel?

80kW, 30kW 82.55kW, 28.45kW 75.55kW, 24.45kW 85.45kW, 24.55kW
Answer Explanation

MCQs 6: If two transformers are operated in parallel with voltage ratio of transformer 1 slightly greater than that of 2. E1 and E2 are the induced emf of transformer 1 and 2, and Z1 and Z2 are the impedances then the circulating current is given by

(E1-E2) / (Z1+Z2) (E1+E2) / (Z1+Z2) (Z1-Z2) / (E1-E2) (Z1-Z2) / (E1+E2)
Answer Explanation

MCQs 7: For the same excitation voltage and winding currents, the autotransformer gives

Less output than two winding transformer Equal to the output of two winding transformer Half of the output of two winding transformer More than the output of the two winding transformer
Answer Explanation

MCQs 8: In a step down autotransformer, if the transformation ratio increases then the saving of copper

Increases Decreases Remains same None of these
Answer Explanation

MCQs 9: If the transformation ratio of an autotransformer is given by V2 / V1 then the ratio of power transferred to that of input power is given by

(V2-V1) / V1 (V2+V1) / V1 (V1-V2) / V1 V2 / V1
Answer Explanation

MCQs 10: Use of an autotransformer is economical when its transformation ratio is

Near unity Much greater than unity Much lesser than unity None of these
Answer Explanation

MCQs 11: If an autotransformer having transformation ratio equal to 0.6 is supplying a load of 8kw then its power transferred from primary to secondary is given by

3 kW 3.2 kW 3.4 kW 3.5 kW
Answer Explanation

MCQs 12: In an autotransformer if the power transferred inductively is equal to the power conducted through, then transformation ratio is given by

1 0.5 2 0
Answer Explanation

MCQs 13: Whether the given autotransformer is step up or step down, its VA rating is always

Greater than the two winding transformer Equal to the two winding transformer lesser than the two winding transformer cannot say
Answer Explanation

MCQs 14: Compared to the two winding transformer, in an autotransformer the leakage reactance and copper losses is

less, more less, less more, more more, less
Answer Explanation

MCQs 15: If a two winding transformer is converted into an autotransformer by applying additive polarity and subtractive polarity which results in the secondary voltages of 1840 and 1810 volts. Then the primary and secondary voltages of transformer are

1800V, 50V 1810V, 40V 1820V, 30V 1825V, 15V
Answer Explanation

MCQs 16: A star connected three phase transformer is provided with tertiary delta connected winding which allows the flow of

Second harmonic of exciting current Third harmonic of exciting current Fifth harmonic of exciting current Seventh harmonic of exciting current
Answer Explanation

MCQs 17: A ferro resonant transformer regulation is also known as

Constant current transformer Constant voltage transformer Variable current transformer Variable voltage transformer
Answer Explanation

MCQs 18: In a constant voltage transformer, the primary winding and secondary winding is formed by the

capacitor, linear inductor Non linear inductor, capacitor Linear inductor and non linear inductor Capacitor, non linear inductor
Answer Explanation

MCQs 19: A constant voltage transformer is fed with the sinusoidal input voltage. Its output is

Sinusoidal Flat topped Saw tooth Zig-zag
Answer Explanation

MCQs 20: The output voltage of constant voltage transformer contains excessive harmonics which can be filtered out by using

RC filter RL filter LC filter None of these
Answer Explanation

MCQs 21: The constant voltage transformers are most commonly used in

Personal computers Arc welding Power distribution Electric cars
Answer Explanation

MCQs 22: In the operation of constant current transformer, two magnetic fields are produced. The magnetic field produced in the secondary is

In the same direction of magnetic field produced in the primary In the opposite direction of magnetic field produced in the primary Perpendicular to the direction of magnetic field produced in the primary Both (b) and (c)
Answer Explanation

MCQs 23: The constant current transformer are mainly used for

Supplying series connected street light Personal computers Arc welding Electric toys
Answer Explanation

MCQs 24: The high leakage impedance transformers are suitable for the applications of

Arc welding Personal computers Street lights Electric lamp
Answer Explanation

MCQs 25: Small iron core transformers used in certain frequency range is also called audio frequency transformer. The audio frequency range is

20 t0 2000 Hz 20 to 20000 Hz 2 to 2000 Hz 200 to 20000 Hz
Answer Explanation

MCQs 26: Pulse transformers are small in size. The leakage inductance and permeability of alloy used is

Low, high Low, low High, low High, high
Answer Explanation

MCQs 27: In a three phase transformer, the angle between two consecutive cores is

30 degree 60 degree 120 degree 150 degree
Answer Explanation

MCQs 28: In a three phase transformer, the current flowing in three primaries produces three corresponding fluxes. The sum of these three fluxes at any instant is

Zero Three times of any individual flux One third of any individual flux None of these
Answer Explanation

MCQs 29: A bank of three single phase transformer can be used for obtaining the three phase output. Three magnetic circuits produced in case of a bank of three single phase transformer and in case of single phase transformer are

Linked, independent Independent, linked Linked, linked Both are independent
Answer Explanation

MCQs 30: For the star - star connection of three phase transformer, the phase angle between the phase voltages and line voltages on both primary and secondary side is

0 degree 30 degree 60 degree 120 degree
Answer Explanation

Related Topics

About Us | Contact Us | Privacy Policy
ABOUT US
Category
Who We Are

TasDia Network, this platform not only provides you the best educational stuff but besides this, we are creating thousands of new ideas to making your signature and planning much more on a single platform.

© 2020-2023, TasDia Network

All rights of the publication are reserved by tasdia.com.