In a.c. voltage regulator with R-L load

A)the current leads the voltage
B)current will lead or lag the voltage depending on the L/R ratio 
C)the voltage lags the current
D)the voltage leads the current

Load voltage in a d.c. chopper circuit is given by / d.c.

A)d.c. supply voltage /duty cycle 
B)Duty cycle X d.c. supply voltage 
C)Duty cycle/ d.c. supply voltage
D)1/(duty cycle X d.c. supply voltage)

A thermistor has a resistance of 3.98 Kilo Ω at 0 °C and 0.794 Kilo Ω at 50 °C. If the relation between resistance and temperature is RT = a RO e b/T, the value of constant b is

A)2845

B)1845

C)4845

D)3845

Zener breakdown occurs due to breaking of covalent bonds by the strong electric field set up in the depletion region by the

A)Reverse coupling 
B)Reverse voltage 
C)Forward current 
D)Forward voltage

A strain gauge with a resistance of 250 Ω undergoes a change of 0.15 Ω during a test. The strain is 1.5 x 10-4. The gauge factor is

A)4
B)6
C)3
D)1

For a moving charge Q in the presence of both electric and magnetic fields, the total force on the charge is given by

A)F = Q(B + μ x E)
B)F = Q(E - μ x B)
C)F = Q(B - μ x E)
D)F = Q(E + μ x B)

In a 132kV circuit breaker the bushing to ground capacitance is 0.01 microFarad and the transformer inductance succeeding the circuit-breaker is 4H. What will be the voltage appearing across the poles of circuit-breaker as it breaks a magnetising current of 15A flowing in the transformer?

A)300 kV
B)144 kV
C)363 kV
D)282 kV

A 1000 kHz carrier is modulated with 800 Hz audio sine wave, the frequencies present in the output will be

A)1000, 1000.8 kHz
B)999.2, 1000.8 kHz 
C)999.2, 1000 kHz 
D)1000, 1800 kHz 

Which of the following law states that the magnetic field intensity dH produced at a point P, by the differential current element Idl is proportional to the product of Idl and the sine of the angle α between the element and the line joining P to the element and is inversely proportional to the square of the distance R between P and the element?/

A)Ampere's circuit law 
B)Gauss's law 
C)Snell's law 
D)Biot-Savart's law

Converting the signed decimal -1 to 8 bit 2's complement number will result in

A)000000 01
B)111111 10
C)111111 11
D)011111 11

Master-slave J-K flip-flop is used to

A)Eliminate race around condition
B)Improve its reliability
C)Reduce power dissipation
D)Increase its clock frequency

When is the READY signal sampled or checked by the 8085 microprocessor?

A)At the end of each machine cycle
B)At the 2nd state of every machine cycle
C)At the end of each instruction cycle
D)At the 1st state of every machine cycle

Two point charges - 4 μC and 5 μC are located at (1 , 0 , 3) and (1, 4, - 2) respectively, then the potential at (1, 0, 1) assuming zero potential at infinity will be (consider ε0 = 10-9/36π)

A)-9 kV
B)-6 kV
C)6 kV
D)9 kV

A 3-phase, half wave controlled rectifier is connected to a 220V source. If the delay angle is 45 degree and the load resistance is 10 Ohm, what will be the average power dissipation in SCR, if SCR has a forward voltage drop of 1 V?

A)2.5 W
B)4.5 W
C)1.5 W
D)3.5 W

A diffraction pattern of a cubic crystal of lattice parameter a = 3.16 A⁰ is obtained with monochromatic X-ray beam of wavelength 1.54 A⁰, the first line on this pattern was observed to have θ = 30⁰, the interplanar spacing will be

A)1.54 A⁰
B)3.1 A⁰
C)11.2 A⁰
D)9.3 A⁰

The induced dipole moment is proportional to the field strength and the proportionality factor αe is called

A)Electronic polarizability
B)Protonic polarizability
C)Electronic field strength
D)Nuclear polarizability

A complex wave of r.m.s. value 240 V has 20% 3rd harmonic content and 2% 5th harmonic content then the approximate r.m.s. value of the fifth harmonic will be

1. 5.7 V
2. 4.7 V
3. 3.7 V
4. 2.7 V

The impedance of a 100 Ω resistor in series with a 10 mH inductor in the s-domain will be

A) 10+1002 s Ω
B) 10+100−2s Ω
C) 100+10−2 s Ω
D) 100+102 s Ω

The addressing mode used in instruction MOV A, B is

A)Implied
B)Immediate
C)Direct
D)Register

Deep bar rotors are used in induction motors to increase

A)Full load torque
B)Full load current
C)Starting current
D)Starting torque

The series resonant circuit that has its minimum impedance, and thus maximum current, at the resonant frequency, is often described as

A)a reflector circuit
B)an acceptor circuit
C)a deflector circuit
D)a rejector circuit

An air core toroid has 500 turns, mean radius of 14 cm, cross sectional area of 6 cm2. The mmf is 2000 AT, then the approximate value of the field intensity inside the core will be

A)2273 AT/m
B)3273 AT/m
C)1273 AT/m
D)4273 AT/m

In signal generators energy is

A) created
B)generated using a generator
C)converted from a simple d.c. source into a.c. energy at some specific frequency
D)converted from a simple a.c. source into d.c. energy at some specific frequency

Two transformers A and B each rated for 40kVA have core losses of 500W and 250W respectively and full load copper losses of 500W and 750W respectively. Which transformer will be preferred to supply lighting loads with the following output pattern? Four hours: Full load, Eight hours: Half load, Remaining twelve hours: No load

A)Cannot be predicted
B)Either Transformer A or Transformer B
C)Transformer B only
D)Transformer A only

What is the value of duty cycle of the clock signal of 8086 ?

A)50%
B)66%
C)33%
D)20%

If a 3-phase induction motor is running at super synchronous speed for self excitation then the machine

A)Feeds reactive power to the mains
B)Draws reactive power from the mains
C)Feeds real power to the mains
D)Draws real power from the mains

The effect of the even symmetry on Fourier series is that the wave has

A)a constant term and cosine terms only
B)sine terms only
C)a constant term and sine terms only
D)a constant term only

The power loss due to hysteresis in the transformer core of 0.05 m3 volume at 50 Hz frequency having an area of the loop is 800 J/m3 will be

A)2000 W
B)4000 W
C)1000 W
D)500 W

For the given open loop transfer function of a servo system with unity feedback what will be the value of damping ratio? Given G(s)=5/{(s+3)(s+4)}

A)0.57
B)2.25
C)1.75
D)4

In a thyristor the junction temperature is 60 degree C. Thermal power flow between the junction and heat sink is 4W. What will be the thermal resistance between junction and heat sink, if the latter is at a temperature of 20 degree C? /

A)15 degree C/Watt
B)5 degree C/Watt /
C)10 degree C/Watt
D)20 degree C/Watt

In a shaded pole induction motor, shading coils are used to

A)Produce rotating magnetic field  ,
B)Reduce windage losses
C)Protect against sparking
D)Reduce winding losses

The impulse response of an initially relaxed system is e^{-2t} u(t). To produce a response of te^{-2t} u(t) what must be the input?

A)e^{-2t} u(t)
B)e^{-t} u(t)
C)2e^{-t} u(t)
D)1/2e^{-2t} u(t)

The inverse Laplace Transform of (4s-5)/(s2 −s −2) will be / (4s-5)/(s2 −s −2)

A)e2t+3e−t
B)e2t+3et
C)e-2t+3e−t
D)e-2t+3et

What will be the reserve capacity of a power plant having maximum demand 90MW? Given plant capacity factor 0.45 and utilization factor 75%.

1. 90 MW
2. 30 MW
3. 120 MW
4. 60 MW

The magnetic pressure on a piece of magnetic material is well defined by the relation

A)2B2/μ0
B)μ0/ 2B2
C)B2/2μ0
D)2μ0/ B2

If B is the total number of branches of the graph and N is the number of nodes, then total number of links (L) should be

A)(B+N+1)
B)(B+N-1)
C)(B-N-1)
D)(B-N+1)

When an external voltage is applied to a p-n junction making the p-type material positive with respect to the n-type material, then the p-n junction is said to be

A)Voltage divider biased
B)Reverse biased
C)Forward biased
D)Fixed biased

In a two wattmeter method with unity power factor

A) readings of two wattmeters are equal and each reads half of the power
B) readings of two wattmeters are equal but opposite in sign
C) one wattmeter reads zero and other reads all the power
D) any value can be read by each wattmeter

Consider the following program.

MVI A, 75
MVI B, 25
ADD B
DAA
After executing the program, what will be the content of the accumulator?


A) 34
B) 9A
C) 90
D) 00

Which of the following algorithms calculates the amplitude and phase of each harmonic component from a set of time domain samples of the input complex wave signal?

A)Fast Fourier transformer
B)Discrete cosine transform
C)Amplitude transformer
D)Program transformation

If a piece of silver wire has a resistance of 1 Ω, then the resistance of manganin wire of one-third the length and one-third the diameter having specific resistance of manganin 20 times that of silver will be

A)60 Ω
B)30 Ω
C)90 Ω
D)20 Ω