electrical engineering MCQs – Page 235

Practise multiple-choice questions from electrical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

electrical engineering Mcqs

1. economics of power generation 2. analog electronics 3. solid state switching circuits 4. parallel circuits 5. switchgear and protection 6. op amp circuits 7. transistor audio power amplifiers 8. electrostatics 9. heating and welding 10. multi stage transistor amplifiers 11. passive filters 12. network theorems 13. regulated d c power supply 14. a c fundamentals circuits and circuit theory 15. electromagnetic induction 16. power electronics 17. magnetism and electromagnetism 18. transformers 19. modulation and demodulation 20. d c generators 21. semiconductor theory 22. single phase induction motors 23. semiconductor diode 24. hybrid parameters 25. digital electronics 26. oscillators 27. earthing or grounding 28. single stage transistor amplifiers 29. d c motors 30. transistor biasing 31. amplifiers with negative feedback 32. basic electrical 33. electronic instruments 34. synchronous motors 35. field effect transistors fet 36. magnetic circuit 37. control systems 38. industrial drives 39. power generation 40. series parallel circuits 41. transistor tuned amplifiers 42. electrical engineering materials 43. rectifiers and converters 44. integrated circuits 45. scr silicon controlled rectifiers 46. cables 47. polyphase induction motors 48. measurement and instrumentation 49. transistors 50. electrical machine design 51. electrolysis and storage of batteries 52. electric traction 53. transmission and distribution

4681. When a large surge current of very short duration flows through a thyristor then which one of the following device will operate to protect the thyristor ___________?
0

A. Snubber circuit

B. Voltage clamping device

C. Fast acting current limiting device (FACL fuse)

D. CB

4682. n a phase controlled 3 phase ac voltage controller, the harmonic present is__________?
0

A. 2nd

B. 7th

C. 3rd

D. 5th

4683. Dynamic equalizing circuit is used for________________?
0

A. equal division of voltage across each thyristor in parallel

B. equal division of current through each thyristor in parallel

C. equal division of current through each thyristor in series

D. equal division of voltage across each thyristor

4684. Which statement is true ?
0

A. Reverse recovery time ( trr ) > gate recovery time (tgr)

B. Device turn OFF time ( tq ) > reverse recover time (trr)

C. All of these

D. Circuit turn OFF time > device turn OFF time ( tq )

4685. Under over voltage condition impedance offered by the voltage clamping device is__________?
0

A. moderate

B. low

C. infinity

D. High

4686. A string of n parallel SCRs is operated at 72 KA, the rating of each SCR is 1 KA. If derating factor of the string is 0.1. value of n will be___________?
0

A. 60

B. 70

C. 80

D. 90

4687. A combination of synchronized leading edge and trailing edge modulation has also been used to control a____________?
0

A. Boost single phase power factor converter

B. A buck dc dc converter to reduce ripple in the intermediate dc bus capacitor

C. Both A. and B.

D. None f these

4688. Which triggering is the most reliable____________?
0

A. Thermal triggering

B. Forward voltage triggering

C. Gate triggering

D. dV / dt triggering

4689. Electrical power output in a D.C. generator is equal to_____________?
0

A. Mechanical power input iron and friction losses copper losses

B. Electrical power developed in armature iron and copper losses

C. Electrical power developed in armature copper losses

D. Mechanical power input iron and friction losses

4690. The most suited gate pulses given to the AC regulator with R L load can be in the form of____________?
0

A. None of these

B. Continuous signal

C. A train of pulses

D. Large isolating pulse transformer

4691. COOLMOS device can be used in application up to power range of___________?
0

A. 500 VA

B. 1 KVA

C. 2 KVA

D. 100 KVA

4692. LISN is a device used to measure conducted emissions. LISN stands for_____________?
0

A. Line integrated stored network

B. Line impedance stabilization network

C. Line integrated stabilization network

D. Laser integrated stabilization networking

4693. Unipolar modulation is generally used in____________?
0

A. DC DC converters

B. AC AC converters

C. AC DC converters

D. DC AC converters

4694. Thyristor is nothing but a____________?
0

A. Controlled switch

B. Controlled transistor

C. Amplifier with higher gain

D. Amplifier with large current gain

4695. The reverse recovery time of diode is trr = 3 Is and the rate off all of the diode current is di/dt = 30 A/Is. The storage charge current QRR is___________?
0

A. 140 Is

B. 130 Is

C. 135 Is

D. 145 Is

4696. The Graetz bridge makes excellent use of ______________?
0

A. SCR

B. Power transformer

C. Potential transformer

D. Current transformer

4697. In constant frequency PWM, at perturbation the amplitude of the sinusoidal component is a___________?
0

A. Linear function

B. Non linear function

C. None of these

D. Constant function

4698. In commutation PAC stands for_______?
0

A. Phase and commutation

B. Phase angle commutation

C. Phase angle converter

D. Permanent angle converter

4699. A thyristor string is made of a no. of SCR connected in series and parallel. The string have volume and current of 11 KV and 4 KA. The voltage and current rating of available SCRs are 1800 V and 1000 A. For a string efficiency of 90 % let the number of SCRs in series and parallel are a and b respectively. Then the value of a and b will be_____________?
0

A. 4, 6

B. 5, 7

C. 7, 5

D. 6, 4

A. Identical to phase voltage in CSI

B. Identical to line current in VSI

C. Identical to line voltage in a VSI

D. Identical to phase voltage in VSI

Previous Next

Showing 4681 to 4700 of 7381 mcqs