RRB JE Stage II : Electrical Engineering Quiz | 19th August

Dear aspirants,

RRB JE Stage II exam is scheduled to be conducted from 28th August to 1st September 2019. The overall merit for the selection will be made on the basis of the marks scored in stage II, so candidates need to prepare thoroughly for the second stage. To help the aspirants, Adda247 has come up with a study plan in which we will provide you daily quizzes of all technical subjects. The below quiz will be helpful for the candidates who opted Electrical as the exam group in RRB JE stage II. 

Q 1. Overhead system can be designed for operation up to-
(a) 11 kV
(b) 33 kV
(c) 66 kV
(d) 400 kV

S 1. (d)
SOL.
400 KV, in case of overhead transmission lines, the space in between the conductors are more as compared to underground system. And additionally, air acts like the insulation medium for those cables. As those conductors are clipped at very high position, so the clearance from the ground is also ok for those cables. These all features permit together for transmission of Extra High Voltage through the overhead cables. So, the huge amount of 400 KV is transmitted via the overhead lines, with suitable cables and pole structures.

S 2. (b)
SOL.
Voltage regulation of transmission line is defined as the ratio of difference between sending and receiving end voltage to receiving end voltage of a transmission line between conditions of no load and full load. It is also expressed in percentage.

Q 3. High voltage transmission lines use
(a) suspension insulators
(b) pin insulators
(c) both (a) and (b)
(d) none of the above

S 3. (c)
SOL
For the successful operation of power lines, proper selection of insulators is very essential. There are several types of overhead line insulators. Most commonly used types are

 Pin type insulators
 Suspension type insulators
 Strain insulators
 Shackle insulators

Q 4. Overhead lines generally use
(a) copper conductors
(b) all aluminum conductors
(c) A.C.S.R conductors
(d) none of these

S 4. (c)
SOL
ACSR conductors are available in a wide range of steel content – from 6% to 40%. ACSR with higher steel content is selected where higher mechanical strength is required, such as river crossing. ASCR conductors are very widely used for all transmission and distribution purposes.

Q 5. The average power dissipated in 50 Ω resistor in Fig. is –

(a) 2 W
(b) 1.44 W
(c) 3.46 W
(d) 1.25 W

Q 6. The power loss in an electrical circuit can take place in
(a) inductance only
(b) resistance only
(c) capacitance only
(d) all of the above

S 6. Ans.(b)
Sol. Power loss occurs in resistance alone since neither inductance (L) nor capacitance (c) consumes any active power.

Q 7 . Permanent-magnet moving coil instrument can be used for……………..
(a) a.c. work only
(b) d.c. work only
(c) both d.c. and a.c. work
(d) none of the above

S 7 . Ans.(b)
Sol. Permanent-magnet moving coil instrument can be used for dc work

Q 8. Figure shows the single line diagram of a 3 –phase transmission line. The three phase short-circuit fault (i.e. Symmetrical fault) will be

(a) more severe at F_1
(b) more severe at F2
(c) same severe at F1 and F2
(d) none of the above

S 8. Ans.(a)
Sol.
Because impedance of the network up to point F1 will be less than up to F_2.

Q 9. A reversed biased p n junction has………..
(a) very narrow depletion layer
(b) almost no current
(c) very low resistance
(d) large current flow

S 9. Ans.(b)
Sol.
A reversed biased pn junction has almost no current.

Q10. What is the advantage of sectionalizing of power plant?
(a) High reliability
(b) Low capital cost
(c) Low maintenance
(d) Easy operation

S10. Ans (a)
Sectionalizing means installing more number of small units rather than installing a big unit. Doing so enables us to maintain continuity of supply from rest of the units, when one or two units of plant fails. this makes the plant more reliable.

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