Steel Authority Of India Limited : Electrical Engineering Previous Years Solved Papers

Steel Authority Of India Limited

Electrical Engineering Previous Years Solved Papers

26.Decibel is a

• unit of voltage
• unit of power
• ratio of power
• none of these

27.dBm is a

• ratio of power
• unit of power
• unit of voltage
• none of these

28.Decibel is a unit of

• frequency
• impedance
• power ratio
• none of these

29.The absolute unit of resistance is of the dimension of

• velocity
• length
• acceleration
• none of these

30.The absolute unit of inductance is of the dimension of

• time
• length
• mass
• none of these

31.The applied voltage from the circuit being checked is disconnected when an ohmmeter is used because

• the current will decrease the resistance
• the ohmmeter has its own battery
• no current is needed for meter movements
• none of these

32.An accurate voltmeter must have an internal impedance of

• very high value
• very low value
• low value
• none of these

33. A moving –coil instrument can be used to measure

• high frequency a.c.
• low frequency a.c
• both d.c. and a.c
• direct current

34.The voltage drop across the moving coil of a 50-µ A (f.s) PMMC meter at full- scale deflection is ---- the voltage drop across that of a 1-mA (fs) PMMC meter at full-scale deflection.

• less than
• approximately equal to
• greater than
• none of these

35.Deflection of pointer of a permanent-magnet moving-coil meter for fixed current is _______ flux density in the airgap between magnetic pole shoes and coil.

• independent of
• directly proportional to
• inversely proportional to
• none of these

36. A moving-iron meter is useful for voltage measurement at _______frequencies.

• high
• low
• very high
• none of these

37. A thermocouple instruments would be used to measure alternating current only?

• low
• very low
• high
• none of these

38.Which of the following instruments will be used to measure alternating current only?

• moving – iron (attraction-types) ammeter
• moving – iron voltmeter
• permanent-magnet type ammeter
• induction-type ammeter

39. A milliammeter can be used

• only as an ammeter
• as a voltmeter
• both as voltmeter and ammeter
• none of these

40.To measure the e.m.f. of a Weston standard cell, one would use a/an 

• electrostatic voltmeter
• hot-wire voltmeter
• galvanometer
• potentiometer

41.Deflection sensitivity of deflecting plates of cathode ray tube ____ the distance between deflection pates.

• is inversely proportional to
• is directly proportional to
• does not depend on
• none of these

42. Deflection sensitivity of deflecting plates of a cathode ray tube ___the accelerating anode (A3) voltage.

• is inversely proportional to
• is directly proportional to
• does not depend on
• none of these

43.A moving – coil instrument can be used to measure

• direct current
• alternating current
• both direct current and alternating current
• none of these

44. The frequency stability of a crystal oscillator depends upon

• tuned circuit
• crystal
• crystal as well as the tuned circuit
• none of these

45.Hay bridge is usually used for measuring

• resistance
• capacitance
• inductance
• none of these

46. Schering bridge is used for measuring

• capacitance
• inductance
• frequency
• none of these

47. The Wien’s bridge is particularly useful for measuring frequencies of _______value.

• low
• very high
• high
• very low

48. Impedance relay is used to protect

• line within a particular zone
• line beyond a particular zone
• the whole transmission system
• none of these

49. Buchholz relay is used in ______ protection.

• line
• generator
• transformer
• none of these

50. 1 GHz means 100 Hz.

• True
• False

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