Showing posts with label Multiple Choice Questions. Show all posts
Showing posts with label Multiple Choice Questions. Show all posts

Saturday, 18 March 2017

Electrical Engineering MCQs With Answers (Question No 21-30)

10:20  , , ,  No comments

Practice Test: Question Answer (Question No 21-30)

1. Which of the following parameter will be more for 16 gauge copper wire in comparison to 14 gauge copper wire?
    (A) Cost
    (B) Strength
    (C) Resistance
    (D) Weight
2. The length of wire having resistance of 1 ohm/m in a heater rated at 1000 W and 250 V will be
    (A) 250 m
    (B) 125 m
    (C) 62.5 m
    (D) 500 m
3. Power dissipated in a pure capacitor is
    (A) Minimum
    (B) Maximum
    (C) Infinite
    (D) Zero
4. The size of the feeder is determined primarily by
    (A) The current it is required to carry
    (B) The percentage variation of voltage in the feeder
    (C) The voltage across the feeder
    (D) The distance over which the transmission is made
5. Non-conductors whose polarization is caused by an electric field are known as
    (A) Dielectric
    (B) Super-conductors
    (C) Semi-conductors
    (D) Insulators
6. If the diameter of a conductor is double, then its resistance will be reduced to
    (A) Half
    (B) One-fourth
    (C) One-eight
    (D) One-sixteenth
7. One of difficulties encountered with super-conductors is
    (A) The materials become highly magnetic
    (B) Strength is reduced
    (C) Resistance is increased
    (D) Maintenance of low temperature
8. The inductance of a coil can be increased by
    (A) Decreasing number of turns
    (B) Increasing core length
    (C) Using core material of high relative permeability
    (D) All of the above
9. The resistance of a lamp rated at 240 V and 60 watts equal to
    (A) 60 ohms
    (B) 120 ohms
    (C) 240 ohms
    (D) 480 ohms
10. Two resistances of 100 ohms and 0 ohm are connected in parallel. The overall resistance will be
    (A) 100 ohms
    (B) 50 ohms
    (C) Zero ohm
    (D) Any one of the above
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Multiple Choice Questions with Answers on Thyristors (SCR)

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Multiple Choice Questions Answers on Thyristors (SCR)

1. An SCR is a ...... triggered device
(1) Voltage
(2) Current
(3) Voltage as well as current
(4) None of the above


2. In an SCR circuit, the supply voltage is generally ......... that of breakover voltage
(1) Equal to
(2) Less than
(3) Greater than
(4) None of the above


3. When an SCR is turned on, the voltage across it is about ..........
(1) zero
(2) 10 V
(3) 0.1 V
(4) 1V


4. An SCR is turned off when
(1) Anode current is reduced to zero
(2) Gate voltage is reduced to zero
(3) Gate is reverse biased
(4) None of the above


 5. In an SCR circuit, the angle of conduction can be changed by
(1) Changing anode voltage
(2) Changing gate voltage
(3) Reverse biasing the gate
(4) None of the above


6. If firing angle is increased, then the output of an SCR
(1) Remains the same
(2) Is increased
(3) Is decreased
(4) None of the above


7. If gate current is increased, then anode-cathode voltage at which SCR turns ON
(1) is decreased
(2) is increased
(3) remains the same
(4) none of the above


8. An SCR has ........... PN junctions.
(1) Two
(2) Three
(3) Four
(4) None of the above


9. An SCR has ........ semiconductor layers.
(1) Two
(2) Three
(3) Four
(4) None of the above


10. In AC supply,  an SCR can exercise control over
(1) Positive half-cycles only
(2) Negative half-cycles only
(3) Both positive and negative half-cycles
(4) Positive or negative half-cycles


11. AC power in a load can be controlled  by connecting
(1) Two SCRs in series
(2) Two SCRs in parallel
(3) Two SCRs in parallel opposition
(4) None of the above


12. When SCR starts conducting, which loses all control?
(1) Cathode
(2) Gate
(3) Anode
(4) None of the above


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