Q1:- How many poles does a rotating magnetic field of a 3-phase, 400 V, 50 Hz induction motor have a rated speed of 715 r.p.m.?
(A) 2 poles
(B) 4 poles
(C) 6 poles
(D) 7 poles
(E) 8 poles
ANSWER:-E
Q2:-The phase voltage of a star-connected, 3-phase circuit is 230 V. The line voltage will be-
(A) 210 V
(B) 220 V
(C) 230 V
(D) 415 V
(E) 400 V
ANSWER:-E
Q3:-The unit of illumination is:
(A) Decibel
(B) Henry
(C) Coulomb
(D) Lux
(E) Tesla
ANSWER:-D
Q4:-If the resistance of the coil is 15 ohms, impedance of the coil is 25 ohms, the inductive reactance will be :
(A) 20 ohms
(B) 400 ohms
(C) 40 ohms
(D) 10 ohms
(E) 2 ohms
ANSWER:-A
Q5:-When the tube lamp is switched “on”, there is some vibrating sound from the choke. This is due to loose______.
(A) Connection in the choke
(B) Winding turns
(C) Core
(D) Screws in the cover
(E) None of these
ANSWER:-C
Q6:-If the fan is running slowly, the reason may be -
(A) Rotor winding open
(B) Field winding open
(C) Capacitor open
(D) Regulator short
(E) Rotor winding short
ANSWER:-C
Q7:- Which of the following material has the highest electrical conductivity?
(A) Steel
(B) Silver
(C) Aluminium
(D) Lead
(E) Zinc
ANSWER:-B
Q8:- The phase difference between any two phases of a 3-phase supply is :
(A) 60°
(B) 90°
(C) 120°
(D) 180°
(E) None of these
ANSWER:-C
Q9:- Which one of the following derived units of SI system is wrongly matched?
(A) Force – Newton
(B) Pressure – Pascal
(C) Work – Volt
(D) Electrical Conductance - Siemens
(E) Magnetic Flux Density – Tesla
ANSWER:-C
Q10:- Transmission line insulators are generally made up of :
(A) Glass
(B) Porcelain
(C) PVC
(D) Iron
(E) Asbestos
ANSWER:-B
Q11:- Junction box method of wiring is more economical with respect to:
(A) Cable length
(B) Labour
(C) Cost
(D) Both (B) & (C)
(E) All of these
ANSWER:-
Q12:- The distributors for residential areas are:
(A) Three phase four wire
(B) Three phase three wire
(C) Single phase three wire
(D) Either (A) or (C)
(E) None of these
ANSWER:-C
Q13:- Which of the following is NOT a standard transmission voltage?
(A) 132 KV
(B) 222 KV
(C) 400 KV
(D) 750 KV
(E) None of these
ANSWER:-B
Q14:- Dielectric strength is the fundamental property of -
(A) Conductors
(B) Insulators
(C) Semiconductor
(D) Super conductors
(E) None of these
ANSWER:-B
Q15:- The maximum permissible load in a lighting sub-circuit is :
(A) 800W
(B) 850W
(C) 875W
(D) 880W
(E) 900 W
ANSWER:-A
Q16:- Severity of electrical shock will be higher in which of the following?
(A) Dry skin
(B) Thick skin
(C) Thin skin
(D) Wet skin
(E) Will be the same on all skins
ANSWER:-D
Q17:- A motor has become thoroughly wet because of exposure to heavy rains. Before operating the motor, it is necessary to dry it out by-
(A) Wiping it dry with a clean cloth
(B) Keeping it under a ceiling fan
(C) Blowing hot air by using air blower
(D) Placing it in an oven
(E) Any of these
ANSWER:-D
Q18:- The fuse operates due to the ________ effect of current.
(A) Magnetic
(B) Electrostatic
(C) Heating
(D) Chemical
(E) None of these
ANSWER:-C
Q19:- Why are AC magnets made of laminated iron?
(A) For reducing the heating effect
(B) To get better induction
(C) For AC and DC use
(D) For reducing costs
(E) None of these
ANSWER:-A
Q20:- Persons _______ are easy targets of lightning attacks.
(A) Inside a house
(B) Inside a car
(C) Inside a submarine
(D) Lying on the ground
(E) In an open field
ANSWER:-E
answer of 11 quation is D
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