Technical Test SSC JE: Electrical Engineering (EE)- 13

If a sinusoidal voltage source is connected to a power transformer, its no load current would be

Short-circuit test is performed on a transformer with a certain impressed voltage at rated frequency. If the short-circuit test is now performed with the same magnitude of impressed voltage but at a frequency higher than the rated frequency, then

If a 230 V DC series motor is connected to a 230 V AC supply, then the motor will

A pair of similar DC shunt generators operate in parallel and supply a common load. It is
required to switch-off machine 1 and allow machine 2 to supply the entire load. The
following operations are to be used to achieve this
1. Switch-off the main switch of machine 1.
2. Reduce the field current of machine 1.
3. Increase the field current of machine 2.
4. Ensure that machine 1 just floats.
The correct sequence of these operations is

Match List-I with List-II and select the correct answer using the codes given below the lists.

As compared to DOL starting, a cage induction motor with star-delta starting shall have

The speed of a 3-phase induction motor operating in its stable region

Match List-I (power factor) with List-II (armature reaction of an alternator) and select
the correct answer using the codes given below the lists

While a 2-pole AC servomotor is in operation, if the voltage across the control field winding becomes zero, then the motor has a tendency to run as a single-phase induction motor. To prevent this

Which of the following single-phase motor has highest starting torque

If an AC servomotor has one of its winding excited by AC, then voltage measured at the other winding with rotor running will be

On which one of the following cycles does a modern steam plant work

The most appropriate operating speeds in rpm of generator used in thermal, nuclear and hydropower plants would be

In the network as shown in figure the marked parameters are per unit impedances. The busadmittance matrix of the network is

The Buchholz relay protects a transformer from

If the fault current is 3000 A for a relay with a plug setting of 50% and CT ratio of 1000 : 1,the plug setting multiplier would be

Maloperation of differential protection of transformers due to magnetizing in rush current is prevented by

In twBo wattmeter method of measuring 3-phase power, power factor is 0.5, then one of the wattmeter will read

Schering bridge is used to

Following figures show four bridges. Which figure is Owen's bridge

The power in a resistor R is estimated measuring the voltage and current using voltmeter-ammeter method. Two different arrangements can be used as shown in circuit I and II. Less erroneous results are obtained adapting

A CRO uses

The latching current of SCR is 18 mA. Its holding current will be

The maximum  in a SCR is

In the figure below the, current of 1A flows through the resistance of

Find the value of Vx in the given figure

Which of the following is correct regarding autotransformer

In a three-phase D/Y transformer shown in the figure, the phase displacement of secondary line voltage with corresponding primary line voltages will be

If the speed of a DC motor increases with load torque, then it is a

A 3-phase slip-ring induction motor is wound for 4-poles on stator and 6-poles on rotor.When 3-phase balanced voltage source at 50 Hz is applied to the motor, it will run at

The phasor diagram of a synchronous machine connected to an infinite bus is shown in the figure. The machine is acting as a

Match List-I with List-II and select the correct answer using the codes given below the lists.

Which of the following capacitors start splitphase induction motors will have the largest value of capacitance

An AC servomotor exhibits

In hydro power stations, what is an enlarged body of water just above the in take and used as a regulating reservoir

Resistance switching is normally resorted in case of

 A Mho relay is a

Match List-I (Relays) with List-II (Protection) and select the correct answer using the codes
given below the lists:

The limiting errors of measurement of power consumed by and the voltage error resistanceare + 2% and + 3.5% respectively. The limiting error of measurement of resistance will be

In a gravity controlled instrument, the deflection angle is proportional to

The problem of electro-static coupling in a transformer is acute at

For power measurement of three-phase circuit by two wattmeter method, when the value of power factor is less than 0.5 lagging

Which bridge is used to determine frequency

Match List-I with List-II and select the correct answer using the codes given below the lists

In the Owen's bridge shown in below figure,Z₁ = 200 Ð 60º, Z₂ = 400 Ð – 90º, Z₃ = 300Ð 0º,Z₄ = 400 Ð 30º. Then, choose the correct statement

Match List-I (Speed/torque regime in a DC motor) with List-II (The control methods
suitable for the same) and select the correct answer using the codes given below the lists.

In the circuit shown below, diodes have cut-in voltage of 0.6 V. The diode in On state is/are

In the circuit of the figure, the value of the voltage source E is

In a nuclear power station using boiling water reactor, water is used as

In a DC transmission line

A heater connected to 230 V main supply draws a current of 7.5 A, then what is the
resistance of heating element

Find the equivalent resistance between the nodes P and Q in both of the different cases

The resistance of eureka wire is 2.5 W. What is the value of specific resistance of wire of 14m length and diameter of 0.14 cm

In the figure, a carbon resistor has band of different colours on its body. The resistance of the following body is

A current of 16A is distributed in a circuit having two branches when connected on 220 V supply. If the resistance of one branch is 20W,then find the resistance of other branch and power taken by both the branches.

Determine the electrical energy of a circuit, if the current flowing from the source is 5A for duration of 2s and the resistance of the circuit is 5W

In which of the following, it is not desired to attain the condition of maximum power transfer

For which type of the following Thevenin's and Norton's equivalents cannot be developed

Two two-port networks are connected in cascade. The combination is to represent as a single two-port networks. The parameters of the network are obtained by multiplying the individual

Consider the following statements
1. Interpole windings are connected in series with armature winding
2. Polarity of interpole must be the same as that of the main pole in advance
3. Distortion of the main field under the pole shoes is not affected by the use of interpoles.

Of these statements regarding inter pole used in DC motors, the correct statement(s) is/are

'Crawling' in an induction motor is due to

Match List-I (type of single-phase motor) with List-II (type of appliance) and select the correct answer using the codes given below the lists.

A capacitor-start single-phase induction motor is switched-on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will

Match List-I (Classification of head) with List- II (Types of turbine) and select the correct
answer using the codes given below the lists.

In a nuclear power station using boiling water reactor, water is used as

A thermal power plant has installed capacity of 15000 MW. The annual load factor is 60% and capacity factor is 50%. The reverse capacity of the plant will be

If X is the system reactance and R is the resistance, the power transferred is maximum when

Match List-I (Types of relays) with List-II (Types of protection) and select the correct
answer using the codes given below the lists.

The CT supplies current to the current coil of a wattmeter power factor meter, energy meter and an ammeter. These are connected as

Wien’s bridge is useful for measuring

X and Y plates of a CRO are connected to unequal voltages of equal frequency with phase shift of 90°. The Lissajaus figure on the screen will be

R1 and R4 are the opposite arms of a Wheat stone bridge as are R3 and R2. The source voltage is applied across R1 and R3. Under balanced conditions which one of the following is true?

A series circuit has two pure elements with entire network voltage and current equation as

V= 10 sin (l00 t + 80°) VI= 5 cos (l00 t + 50°)

A Then the two elements in the network will be

Consider the following statements in respect of important features of IGBT
1. It has a high impedance gate as that of a MOSFET.
2. It has a low on state voltage as that of a BJT.
3. It can block negative voltages as in the case of GTO.
Which of these statements are correct?

In the figure shown if we connect 2 V with internal resistance 1 Ω at AA’ with positive terminal at A’, the current through R in ampere is

Find voltmeter reading of the circuit shown below 

The power supplied to the circuit in figure, by the voltage and current sources respectively are

If a fixed amount of power is to be transmitted over a certain length with fixed power loss, it can be said that volume of conductor is

Consider the following network 

The power dissipated across 4 Ω resistor is

The component of excitation current present in Δ-connected secondary of transformer are

In a loaded DC motor, if the bushes are given a shift from the inter polar axis in the direction of relation, then the communication will

The time constant for the given circuit in second is

In a thyristor, which of the following is correct?

Once SCR starts conducting forward current, its gate losses control over

For parallel operation of transformers, which  condition is essential?
1. Same voltage ratio.
2. Same pu leakage impedance.
3. Same Xe|re ratio.
4. Same polarity.
 

Match List-I with List-II and select the correct answer using the codes given below the lists.

A galvanometer of resistance 15 Ω gives full scale deflection for a current of 2 mA. Calculate the shunt resistance needed to convert it to an ammeter of range 0 to 5 A.

A moving coil galvanometer has a resistance of 25 Ω and gives a full scale deflection for a currentof 10 mA. How will you convert it into voltmeter having range 0–100 V?

Two transformers of different kVA ratings working in parallel, share the load in proportionto their ratings when their

In a transformer zero voltage regulation at fullload is

The torque speed characteristic of a repulsion motor resembles which of the following DC motor characteristic

A D/D connected transformer is connected to V/V connected transformer. The ratio of VA rating of V/V connected transformer and D/D connected transformer is

Consider the following statements:

 The armature torque in a DC motor is a function of
1. Field flux
2. Armature current
3. Speed
4. Damping
Which of the above statements is/are correct
 

Insulating materials have the function of 

A 50 Hz, 3-phase synchronous generator has inductance per phase of 15 mH. The capacitance of generator and circuit beaker is 0.002 mF. What is its natural frequency of oscillation

Relative permeability of iron is 4000. What is its magnetic susceptibility

(i) The peak voltage of an AC supply is 300V. What is the rms voltage
(ii) The rms value of current in an AC circuit is 10A. What is the peak current