ELECTRICAL QUESTIONS

ELECTRICAL ENGINEERING OBJECTIVE QUESTIONS
1.A resistance of 10 ohm is connected across a supply of 200V. If resistance R is now connected in parallel with a 10 ohm resistance, the current drawn from the supply gets doubled. The value of unknown resistance R is
(a) 5 ohm
(b) 20 ohm
(c) 10 ohm
(d) 15 ohm
Ans : c

2. The close path of the flux around any current carrying circuit is referred asCircuit.
(a) Magnetic
(b) Electric
(c) Electromagnetic
(d) None of these
Ans : a

3. Magnetic field strength is equal to
(a) mmf. L
(b) L/ mmf
(c) mmf/ L
(d) 1/mmf.L
Ans : c

4. Peak inverse voltage of bridge rectifier is as that of centre-tap circuit.
a). Same
b). Twice
c). Half
d). Four times
Ans. c

5. Peak Resistance of the diode is increased when
a). Forward biased
b). Reverse biased
c). Both forward and reverse biased
d). Either a or b
Ans. b

6. The number of lines of force passing through the secondary coil S when unit current changes in the primary coil P are called
(a) Self inductance
(b) Mutual inductance
(c) Self induction
(d) Mutual induction
Ans : c

7. The current flowing in an electrical circuit is due to the existence of
(a) mmf
(b) emf
(c) Resistance
(d) Reluctance
Ans : b

8. The magnetic flux flow through a magnetic circuit is due to
(a) mmf
(b) emf
(c) Resistance
(d) Reluctance
Ans : a

9. The on-line UPS is also called as
a). Stand-by UPS
b). Line Interactive UPS
c). Off line UPS
d). Current line UPS
Ans. b

10. Expression for magneto-motive force is
(a) N/I
(b) 1/NI
(c) I/N
(d) IN
Ans : d

11. Unit of mmf is
(a) Ampere /Volt
(b) Ampere- turns
(c) Volt
(d) Volt/Ampere
Ans : b

12.After the valley point UJT acts as
a).transister
b).amplifier
c).contoller
d).forward PN Diode
Ans:d

13.UJT used in
a.pulse generator
b. electric circuit
c.either (a)&(b)
d.none of these
Ans:a

14.Diac is used as
a.triggering device
b. pulse generator
c. amplifier
d.contoller
Ans:a

15.Triac is
a.Two transister device
b.two diodes device
c.two diacs device
d.two SCR device
Ans:d

16.When Gate current is equal to zero,SCR acts as
a.Diode
b.transister
c.PNPN Diode
d.none of these
Ans:c

17..Triac has
a.one terminal
b.two terminal
c.three terminal
d.four terminal
Ans:c

18.Terminals of SCR
a.gate,emitter
b.gate,base.collector
c.anode,cathode,gate
d.none of these
Ans:c

19.A term ‘intrinsic standoff ratio’ used in
a.Diode
b.UJT
c.PNPN Diode
d.SCR
Ans:b

20.Which one is used as triggering device
a.Diode
b.UJT
c.PNPN Diode
d.none of these
Ans:b

21.SCR is used as
a.pulse generator
b. amplifier
c.contoller
d.none of these
Ans:c

22. Terminals of transistor
a.gate,emitter
b.gate,base.collector
c.anode,cathode,gate
d.base,emitter,collector
Ans:d

23.At room temperature, extrinsic semiconductor is
a)conductor
b)poor conductor
c)partially conductor
d)none of these
Ans:b

24.Which one is trivalent impurity
a)boron
b)antimony
c)silicon
d)none of these
Ans:a

25.Which one is pentavalent impurity
a)boron
b)antimony
c)silicon
d)none of these
Ans:b

26.Resistance of an ideal diode, resistance during reverse biasing
(a) Zero
(b) Unity
(c) Maximum
(d) infinite
Ans:d

27. In CB Configuration of transistor, the output impedance is
(a) High
(b) medium
(c) Low
(d) none of these
Ans:a

28. In CB Configuration of transistor, voltage gain is
(a) High
(b) medium
(c) Low
(d) none of these
Ans:a

29. In CB Configuration of transistor, current gain is
(a) High
(b) medium
(c) Low
(d) almost one
Ans:d

30. In CE Configuration of transistor, the input impedance is
(a) High
(b) medium
(c) Low
(d) none of these
Ans:b

31. In CE Configuration of transistor, the output impedance is
(a) High
(b) medium
(c) Low
(d) none of these
Ans:b

32. In CC Configuration of transistor, the output impedance is
(a) High
(b) medium
(c) Low
(d) none of these
Ans:c

33. An ideal diode resistance has———resistance during forward biasing
(a) Zero
(b) Unity
(c) Maximum
(d) Minimum
Ans:a

34. Transistor is used as
(a) Switch
(b) Amplifier
(c) Both (a) & (b)
(d) None of these
Ans:c

35. Transistor is ———–Device
(a) Bipolar
(b) Unipolar
(c) Constant current
(d) Constant voltage
Ans:a

36. Diode is used as
(a) Regulator
(b) Inverter
(c) Current Regulator
(d) Rectifier
Ans:d

37. Zener diode acts as
(a) Rectifier
(b) Regulator
(c) Inverter
(d) None of these
Ans:b

38. Diode is ———–Device
(a) Bipolar
(b) Unipolar
(c) Constant current
(d) Constant voltage
Ans:b

39. Ripple factor for half wave rectifier
(a) 1.11
(b) 1.21
(c) 1.5
(d) 0.48
Ans:b

40. Ripple factor for full wave rectifier
(a) 1.11
(b) 1.21
(c) 1.5
(d) 0.48
Ans:d