electrical engineering Mcqs
1. economics of power generation2. analog electronics3. solid state switching circuits4. parallel circuits5. switchgear and protection6. op amp circuits7. transistor audio power amplifiers8. electrostatics9. heating and welding10. multi stage transistor amplifiers11. passive filters12. network theorems13. regulated d c power supply14. a c fundamentals circuits and circuit theory15. electromagnetic induction16. power electronics17. magnetism and electromagnetism18. transformers19. modulation and demodulation20. d c generators21. semiconductor theory22. single phase induction motors23. semiconductor diode24. hybrid parameters25. digital electronics26. oscillators27. earthing or grounding28. single stage transistor amplifiers29. d c motors30. transistor biasing31. amplifiers with negative feedback32. basic electrical33. electronic instruments34. synchronous motors35. field effect transistors fet36. magnetic circuit37. control systems38. industrial drives39. power generation40. series parallel circuits41. transistor tuned amplifiers42. electrical engineering materials43. rectifiers and converters44. integrated circuits45. scr silicon controlled rectifiers46. cables47. polyphase induction motors48. measurement and instrumentation49. transistors50. electrical machine design51. electrolysis and storage of batteries52. electric traction53. transmission and distribution
3901. Three 47 ? resistors are connected in parallel across a 110 volt source. The current drawn from the source is approximately_______________?
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A. 7.06 A

B. 47 mA

C. 2.3 A

D. 780 mA

3902. If there are a total of 120 mA into a parallel circuit consisting of three branches, and two of the branch currents are 40 mA and 10 mA, the third branch current is_________________?
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A. 50 mA

B. 120 mA

C. 40 mA

D. 70 mA
3903. The currents into a junction flow along two paths. One current is 4 A and the other is 3 A. The total current out of the junction is_____________?
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A. 1:00 AM

B. 7 A

C. the larger of the two

D. unknown

3904. The following resistors are in parallel across a voltage source: 220? , 470? , and 560? . The resistor with the least current is______________?
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A. impossible to determine without knowing the voltage

B. 560 ?

C. 220 ?

D. 470 ?

3905. Six resistors are in parallel. The two lowest-value resistors are both 1.2 k?. The total resistance______________?
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A. is less than 600 ?

B. is greater than 1.2 k?

C. is less than 1.2 k?

D. is less than 6 k?

3906. When an additional resistor is connected across an existing parallel circuit, the total resistance____________?
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A. increases by the value of the added resistor

B. decreases by the value of the added resistor

C. decreases

D. remains the same

3907. If one of the resistors in a parallel circuit is removed, the total resistance_____________?
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A. remains the same

B. decreases

C. increases

D. doubles

3908. Five light bulbs are connected in parallel across 110 V. Each bulb is rated at 200 W. The current through each bulb is approximately___________?
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A. 2.2 A

B. 9.09 A

C. 137 mA

D. 1.8 A
3909. With which of the following, a circuit breaker must be equipped for remote operation ?
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A. None of the above

B. Shunt trip

C. Time-delay trip

D. All of the above

E. Inverse time trip

3910. The single phasing relays are used for the protection of_____________?
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A. two single phase motors running in parallel

B. three phase motors

C. single phase motors only

D. two phase motors only

3911. What will be the reflection co-efficient of the wave of load connected to transmission line if surge impedance of the line is equal to load ?
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A. Infinity

B. None of the above

C. Zero

D. Unity

3912. Which of the following parameter can be neglected for a short line ?
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A. Resistance

B. Capacitance

C. Inductance

D. Reactance

3913. A _________ is used to measure the stator % winding temperature of the generator?
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A. thermometer

B. thermocouple

C. resistance thermometer

D. pyrometer

3914. On which of the following effects of electric current a fuse operates ?
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A. Heating effect

B. Electrostatic effect

C. Photoelectric effect

D. Magnetic effect

3915. In order that current should flow without causing excessive heating or voltage drop, the relay contacts should_________________?
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A. be of sufficient size and proper shape

B. be clean and smooth

C. have all above properties

D. have low contact resistance

3916. When a transmission line is energized, the wave that propagates on it is____________?
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A. current wave only

B. voltage wave only

C. Both (A) and (B)

D. power factor wave only

3917. The main function of a fuse is to_____________?
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A. none of the above

B. protect the line

C. prevent excessive currents

D. protect the appliance

E. open the circuit

3918. An efficient and a well designed protective relaying should have_____________?
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A. high speed and selectivity

B. good selectivity and reliability

C. all of the above

D. economy and simplicity

3919. Series capacitors are used to_________________?
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A. improve line voltage

B. none of the above

C. compensate for line inductive reactance

D. compensate for line capacitive reactance

3920. The arcing contacts in a circuit breaker are made of______________?
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A. aluminium alloy

B. copper tungsten alloy

C. porcelain

D. electrolytic copper

3921. The inverse definite mean time relays are used for over current and earth fault protection of transformer against_________________?
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A. heavy loads

B. internal short-circuits

C. all of the above

D. external short-circuits

3922. Relays can be designed to respond to changes in________________?
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A. light intensity

B. all above

C. resistance, reactance or impedance

D. voltage and current

E. temperature

3923. The fuse blows off by___________?
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A. burning

B. none of the above

C. arcing

D. melting
3924. For the protection of power station buildings against direct strokes the requirements are___________?
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A. interception, conduction, dissipation and reflection

B. interception, conduction and dissipation

C. none of the above

D. interception

E. interception and conduction

3925. Shunt capacitance is neglected while considering______________?
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A. short transmission line

B. long transmission line

C. medium transmission line

D. medium and long transmission lines

3926. Admittance relay is __________ relay?
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A. impedance

B. directional

C. none of the above

D. non-directional

3927. In a circuit breaker the basic problem is to________________?
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A. extinguish the arc

B. emit the ionizing electrons

C. transmit large power

D. maintain the arc

3928. Air blast circuit breakers for 400 kV power system are designed to operate in_______________?
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A. 100 microsecond

B. 50 millisecond

C. 0.5 sec

D. 0.1 sec

3929. In a single bus-bar system there will be complete shut down when____________?
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A. fault occurs on the bus itself

B. fault occurs on neutral line

C. fault occurs with respect to earthing

D. two or more faults occur simultaneously

3930. Which of the following is the least expensive protection for overcurrent is low voltage system ?
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A. Isolator

B. Air break circuit breaker

C. None of the above

D. Rewireable fuse

E. Oil circuit breaker

3931. D.C. shunt relays are made of_____________?
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A. many turns of thin wire

B. few turns of thick wire

C. many turns of thick wire

D. few turns of thin wire

3932. Which of the following medium is employed for extinction of arc in air circuit breaker?
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A. Oil

B. SF6

C. Air

D. Water

3933. Ionization in circuit breaker is facilitated by___________?
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A. increase of mean free path

B. all of the above

C. increasing field strength

D. high temperature

3934. The power loss is an important factor for the design of_______________?
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A. motor

B. generator

C. transmission line

D. feeder

3935. The ground wire should not be smaller than No _________ copper
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A. 6

B. 2

C. 4

D. 10
3936. If the fault occurs near the impedance relay, the VII ratio will be____________?
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A. higher than that of if fault occurs away from the relay

B. constant for all distances

C. none of the above

D. lower than that of if fault occurs away from the relay
3937. A transmission line is protected by_____________?
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A. inrush protection

B. distance protection

C. time graded and current graded over current protection

D. both (B) and (C)

E. none of the above

3938. Arc in a circuit breaker is interrupted at___________?
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A. zero current

B. minimum voltage

C. maximum voltage

D. maximum current

3939. The under voltage relay can be used for______________?
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A. motors

B. transformers

C. busbars

D. all of the above

E. generators

3940. For which of the following protection from negative sequence currents is provided ?
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A. Transmission line

B. Transformers

C. Generators

D. Motors

3941. To limit short-circuit current in a power system are used______________?
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A. earth wires

B. reactors

C. isolators

D. H.R.C. fuses

3942. The current zero interruption, in oil and air blast circuit breakers, is achieved by____________?
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A. lengthening of the gap

B. cooling and blast effect

C. both (A) and (B)

D. deionizing the oil with forced air

E. none of the above

3943. To protect most of the electrical equipment handling low power, the types of relays used are______________?
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A. thermocouple

B. electronic and bimetallic

C. both (A) and (B)

D. none of the above

3944. Resistance grounding is used for voltage between_________________?
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A. 33kVto66kV

B. 3.3kVandllkV

C. HkVto33kV

D. none of the above

3945. A thermal protection switch can protect against_____________?
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A. temperature

B. overload

C. short-circuit

D. over voltage

3946. By which of the following methods major portion of the heat generated in a H.R.C. fuse is dissipated ?
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A. Radiation

B. All of the above

C. Conduction

D. Convection

3947. Burden of a protective relay is the power______________?
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A. none of the above

B. required to operate the circuit breaker

C. absorbed by the circuit of relay

D. developed by the relay circuit

3948. Circuit breakers are essentially______________?
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A. any of the above

B. transformers to isolate the two systems

C. arc extinguishers

D. circuits to break the system

E. current carrying contacts called electrodes
3949. Fault diverters are basically____________?
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A. circuit breakers

B. fuses

C. relays

D. fast switches
3950. When a wave propagates on a transmission line, it suffers reflection several times at_____________?
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A. tapping

B. sending end

C. load end

D. sending and other end

E. all of the above