(Solved) J. B. Gupta important questions from model test paper with solution

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Important questions of JB Gupta book Model Test Paper 2 :

(We are working to provide detailed solutions of each question. We are updating this page.)


Question 1 :

In a magentic material, hysteresis loss takes place primarily due to 

(a) rapid reversals of its magnetisation 

(b) flux density lagging behind magnetis ing force 

(c) molecular friction 

(d) its high retentivity

Ans: D

 

Question 2 :

On which of the following factors does the resolution of a potentiometer depend?

(a) Size of wire 

(b) Type of contact

(c) Composition of wire material 

(d) Shape of wire cross-section

Ans: A

 

Question 3 :

The braking retardation is usually in the range

(a) 0.15 to 0.30 km phps 

(b) 0.30 to 0.6 km phphs 

(c) 0.6 to 2.4 km phps 

(d) 3 to 5 km phps 

(e) 10 to 15 km phphs

Ans: D


Question 4 :

Which of the following methods is used for reduction/elimination of harmonic torques?

(a) Chording

(b) Integral slot windings

(c) Skewing

(d) Increase in air gap length 

(e) All of the above

Ans: E


Question 5 :

A permanent magnet 

(a) attracts some substances and repels others

(b) attracts all paramganetic substances and repels others

(c) attracts only ferromagnetic substances (d) attracts ferromagnetic substances and repeals all others

Ans: A


Question 6 :

In order to convert the angular position of a shaft into an electric signal, which of the following electromagnetic transducers can be used?

(a) A.C. servemotor

(b) Thermocouple 

(c) Rotary LVDT

(d) Synchrous

Ans: D


Question 7 :

Which of the following motors one will choose to drive the rotary compressor? 

(a) D.C. shunt motor

(b) D.C. series motor

(c) Universal motor

(d) Synchronous motor

Ans: D


Question 8 :

A pilot exciter is provided on generators for which of the following reasons ?

A. To excite the poles of main exciter

B. To provide requisite starting torque to main exciter

C. To provide requisite starting torque to generator

D. None of the above

Ans: A


Question 9 :

A parallel resonant circuit can be used 

(a) as a high impedance 

(b) to reject a small band of frequencies

(c) both (a) and (b)

(d) to amplify certani frequencies

Ans: C


Question 10 :

Current density in the rotor bars of an induction motor may be taken between

(a) 1.5 to 2.5 A/mm² 

(b) 3 to 4 A/mm²

(c) 4 to 7 A/mm²

(d) 8 to 10 A/mm²

Ans: C


Question 11 :

The property of a coil carrying a changing current to induce a counter e.m.f. is called

(a) self inductance

(b) mutual inductance

(c) series aiding inductance

(d) series opposing inductance

Ans: A


Question 12 :

Wien bridge is usually used for the meas urement of which of the following?

(a) Frequency 

(b) Capacitance 

(c) Resistance 

(d) Inductance

Ans: B


Question 13 :

An A/D converter uses for reference purposes

(a) a flip-flop 

(b) a sawtooth generator

(c) d.c. voltage 

(d) set of keys

Ans: B


Question 14 :

Hall effect can be used to measure

(a) carrier concentration

(b) electric field intensity 

(c) magnetic field intensity

(d) none of the above

Ans: C


Question 15 :

Generally....flip-flops are used in shift

registers 

(a) D

(b) T

(c) SR

(d) JK

Ans: D


Question 16 :

To increase the Q-factor of an inductor it is wound with

(a) longer wire 

(b) coiled coil wire

(c) thicker wire 

(d) thinner wire

Ans: C


Question 17 :

The function y(s) :(2s² + 2s + 1)/(s² +2s +2) is a

(a) Hurwitz polynomial

(b) positive real function

(c) not a positive real function

(d) none of the above

Ans: B

Degree of numerator is not exceeding degree of denominator by more than unity. Here degree of numerator and denominator are same. So it is positive real function.


For any queries in solutions please comment below. 



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