Electrical and Electronics Engineering Mid - II, November - 2014

1.Which of the following supply is given to the rotor winding of 3-Phase Induction Motor:
  • AC supply
  • Pulsating supply
  • DC supply
  • No Supply
Answer: D
2.AC generators are rated in ___________
  • MVA or KVA
  • kVAR
  • MW
  • H.P
Answer: A
3.In a 3 - phase induction motor, the rotor speed is ________ the synchronous speed
  • smaller than
  • greater than
  • equal to
  • none of the above
Answer: A
4.In a PN diode, with the increase of the reverse bias voltage the reverse current
  • increases
  • decreases
  • remains constant
  • may increase or decrease
Answer: C
5.The picture tube of a CRO converts electrical energy into _________ energy
  • Mechanical
  • Light
  • Electric
  • Rotational
Answer: B
6.Number of p-n junctions in a thyristor ______________.
  • 1
  • 2
  • 3
  • 4
Answer: C
7.The turn on voltage of the Ge junction diode is nearly
  • 0.7 V
  • 0.3 V
  • 0.2 V
  • 0.1
Answer: B
8.In the forward region of its characteristics a diode appears as
  • Off switch
  • a high Resistance
  • a capacitor
  • ON switch
Answer: D
9.CROs are used to determine
  • Amplitude
  • Phase
  • Frequency
  • All of the above
Answer: D
10.A transistor is a __________ operated device
  • current
  • voltage
  • both current and voltage
  • none of the above
Answer: A
11.If a 4 pole induction motor has a synchronous speed of 1500 rpm then supply frequency is _________
Answer: 50 Hz
12.If the frequency of 3-phase supply to the stator of 3-phase induction motor is increased, then synchronous speed is ________
Answer: Increases
13.In a CRT, ________________ deflecting plates cause the beam to deflect in X-direction.
Answer: Horizantal or X deflecting plates
14.The maximum voltage that can be applied to a diode without destroying it is called ___________ voltage
Answer: Peak inverse
15.An ideal diode conducts in forward direction with __________ resistance
Answer: Zero
16.The leakage currents in the transistors are due to __________ carriers
Answer: minority
17.Ripple factor of the half wave rectifier is ___
Answer: 1.21
18.A _______________ is a device with four layers and three terminals including a gate signal
Answer: Thyritor
19.The SCR is made of ___________________________
Answer: silicon
20.The ratio of IC and IE gives the _____________ of transistor
Answer: alpha