Q1:-Out of the followings, which one is correct in case of a circuit breaker?
(1) Making capacity = 2.55 × braking capacity
(2) Braking capacity = 2.55 × making capacity
(3) Making capacity = 1.8 × braking capacity
(4) Braking capacity = 1.8 × making capacity
ANSWER:-1
Q2:- The steady-state fault current during a 3 phase terminal fault on a generator is limited by:
(1) Transient reactance of the generator
(2) Sub-transient reactance of the generator
(3) Synchronous reactance of the generator
(4) DC off-set during the instant of the fault
ANSWER:-3
Q3:- A 3-phase delta connected squirrel cage induction motor when started with a DOL starter has a starting ls torque of 600 NM. Its starting torque when star delta starter is used:
(1) 600 NM
(2) 200 NM
(3) 300 NM
(4) 1200 NM
ANSWER:-2
Q4:- Making current of a circuit breaker refers to:
(1) Steady state rated current
(2) Average value of transient short circuit current
(3) R.M.S. value of the short circuit current at the time of
(4) Equal to the fault current
ANSWER:-3
Q5:- In case of a ‘High Voltage DC’ transmission, how many minimum conductors are required?
(1) One
(2) Two
(3) Three
(4) Four
ANSWER:-1
Q6:- Which of the following motor has squirrel cage winding on the stator:
(1) 3 phase squirrel cage induction motor
(2) Single phase squirrel cage pump motor
(3) Single phase ceiling fan induction motor
(4) Single phase table fan induction motor
ANSWER:-3
Q7:- In order to switch-off and EHV circuit for maintenance, the following sequence is adopted:
(1) Open the circuit breaker, open the isolator, operate the earth switch
(2) Operate the earth switch, open the isolator, open the circuit breaker
(3) Open the isolator, operate the earth switch, open the circuit breaker
(4) Open the isolator, open the circuit breaker, operate the earth switch
ANSWER:-1
Q8:-Why are shunt reactors connected at the receiving end of long transmission line system:
(1) To increase the terminal voltage
(2) To compenstate voltage rise caused by capacitive charging at light load
(3) To improve power factor
(4) None of these
ANSWER:-2
Q9:-A 10Ω resistor is connected in parallel with a 15Ω resistor and the combination in series with a 12Ω resistor. The equivalent resistance of the circuit is:
(1) 37Ω
(2) 27Ω
(3) 18Ω
(4) None of these
ANSWER:-3
Q10:-A nickel coil has a resistance of 13Ω at 50°C. If the temperature coefficient of resistance at 0°C is 0.006/
°C, the resistance at 0°C is:
(1) 16.9Ω
(2) 10Ω
(3) 43.3Ω
(4) None of these
ANSWER:-2
Q11:-The energy used by a 1.5kW heater in 5 minutes is:
(1) 450 000 J
(2) 450 J
(3) 7500 J
(4) None of these
ANSWER:-1
Q12:- What is called the Electro-Motive Force (EMF) of a voltage source?
(1) Terminal voltage when load is applied
(2) Internal voltage when no load is applied
(3) Product of internal resistance and load current
(4) Electric pressure provided to the load
ANSWER:-2
Q13:-A permanent magnet moving coil ammeter has a coil resistance of 99 ohm and Full Scale Deflection (FSD) current of 0.1mA. Shunt resistance is 1 ohm. Current through the meter at 0.5 F.S.D is:
(1) 0.007mA
(2) 0.05mA
(3) 0.023mA
(4) None of these
ANSWER:-2
Q14:-For power measurement of three phase circuit by two wattmeter method, when the value of power factor is less than 0.5 lagging:
(1) One of the wattmeters will read zero
(2) Both give the same readings
(3) One of the wattmeter connections will have to be reversed
(4) Pressure coil of the wattmeter will become ineffective
ANSWER:-3
Q15:-One international ohm is equal to:
(1) 1.00049 absolute ohm
(2) 0.99951 absolute ohm
(3) 0.969 absolute ohm
(4) 1.049 absolute ohm
ANSWER:-1
Q16;-In a uniform electric field, field lines and equipotentials:
(1) Are parallel to one another
(2) Intersect at 45°
(3) Intersect at 30°
(4) Are orthogonal
ANSWER:-4
Q17:-During forward blocking state, the SCR has:
(1) Low current, medium voltage
(2) Low current, large voltage
(3) Medium current, large voltage
(4) Large current, low voltage
ANSWER:-2
Q18:-Turn on time of an SCR can be reduced by using a:
(1) Rectangular pulse of high amplitude and narrow width
(2) Rectangular pulse of low amplitude and wide width
(3) Triangular pulse
(4) Trapezoidal pulse
ANSWER:-1
Q19:-The disruptive critical voltage will:
(1) Decrease with the increase of moisture content in air
(2) Increase with the increase of moisture content in air
(3) Increase with the decrease of moisture content in air
(4) Decrease with the decrease of moisture content in air
ANSWER:-1
Q20:-What type of insulator will be used if the direction of the transmission line is to be changed?
(1) Pin-type
(2) Suspension type
(3) Strain type
(4) Shakle type
ANSWER:-2
Q21:-Which statement is correct:
(1) SF6gas is toxic
(2) SF6gas is lighter than air
(3) SF6gas is yellow in colour
(4) SF6gas has pungent smell
ANSWER:-1
Q22:-One coulomb of electrical charge is contributed by
how many electrons?
(1) 0.625 × 1019
(2) 1.6 × 1019
(3) 1019
(4) None of these
ANSWER:-1
Q23:-A dynamic system with input x(t) and output y(t) is represented by the following
(1) y(t)= f(x(t),t)
(2) y(t)= ax(t) +bx2(t)
(3) y(t)= a xsin(t)
(4) None of these
ANSWER:-1
Q24:-If the current in the armature of d.c series motor is reduced to 5%, the torque of the motor will become
(1) 50% of the previous value
(2) 25% of the previous value
(3) 150% of the previous value
(4) 125% of the previous value
ANSWER:-2
Q25:-If the excitation of an alternator operating in parallel with other alternators decreased, its:
(1) Power factor becomes more leading
(2) Output Kw will change
(3) Power factor becomes more lagging
(4) Power factor becomes unity
ANSWER:-1
Q26:-The output signal of a common-collector amplifier always
(1) Larger than the input signal
(2) In phase with the input signal
(3) Out of phase with the input signal
(4) Exactly equal to the input signal
ANSWER:-2
Q27:-A current is said to be alternating when it changes in:
(1) Magnitude
(2) Direction
(3) Both magnitude and direction
(4) None of these
ANSWER:-3
Q29:-Hysteresis loss in a transformer depends upon:
(1) Frequency
(2) Supply voltage
(3) Square of the frequency alone
(4) Square of the voltage alone
ANSWER:-1
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