Question Bank For BSNL JTO

Please provide me JTO post exam paper issued by Bharat Sanchar Nigam Ltd, so that I can solve it easily?

[pawan]

On your demand I will get the Bharat Sanchar Nigam Ltd, JTO post exam paper so that it would be easy for you to prepare.

Here is the exam paper

1. One of the following statement which is true for relative dielectric constant is -
a) It is dimensionless
b) It is not equal to unity for vacuum
c) Its value for all substances is less than one
d) None
Answer is :- It is dimensionless

2. Pure metals generally have-
a) high conductivity and low temperature coefficient
b) high conductivity and large temperature coefficient
c) low conductivity and zero temperature coefficient
d) low conductivity and high temperature coefficient
Answer is :- high conductivity and large temperature coefficient

3. For small size, high frequency coils, the most common core material is
a) Air
b) Ferrite
c) Powdered ion
d) Steel
Answer is :- Air

4. For an abrupt junction Varactor diode, the dependence of device capacitance (C) on
applied reverse bias (V) is given by-
a) C a V1/3
b) C a V-1/3
c) C a V1/2
d) C a V-1/2
Answer is :- C a V-1/3

5. A superconductor is a-
a) A material showing perfect conductivity and Meissner effect below a critical
temperature
b) A conductor having zero resistance
c) A perfect conductor with highest dimagnetic susceptibility
d) A perfect conductor which becomes resistive when the current density through it
exceeds a critical valueAnswer is :-A material showing perfect conductivity and Meissner effect below a critical
temperature

6. When a semiconductor based temperature transducer has a temperature coefficient of "
2500 mV/0C then this transducer is indeed a-
a) Thermistor
b) Forward biased pn junction diode
c) Reverse biased pn junction diode
d) FET
Answer is :- Forward biased pn junction diode

7. The location of lightning arrestor is -
a) Near the transformer
b) Near the circuit breaker
c) Away from the transformer
d) None
Answer is :- Near the transformer

8. Time constant of an RC circuit increases if the value of the resistance is -
a) Increased
b) Decreased
c) Neither a nor b
d) Both a and b
Answer is :- Increased

9. Intrinsic semiconductors are those which -
a) Are available locally
b) Are made of the semiconductor material in its purest from
c) Have more electrons than holes
d) Have zero energy gaps
Answer is :- Are made of the semiconductor material in its purest from

10. The primary control on drain current in a JFET is exerted by -
a) Channel resistance
b) Size of depletion regions
c) Voltage drop across channel
d) Gate reverse bias
Answer is :- Gate reverse bias

11. The electrical conductivity of metals which is expressed in ohm-1 m-1 is of the order
of -
a) 1010
b) 105
c) 10-4
d) 10-6
Answer is :- 105

12. When biased correctly, a zener diode "
a) acts as a fixed resistance
b) has a constant voltage across it
c) has a constant current passing through it
d) never overheats
Answer is :- has a constant voltage across it

13. The current amplification factor adc is given by "
a) IC/IE
b) IC/IB
c) IB/IC
d) IB/IC
Answer is :- IC/IE

14. Compared to bipolars, FETs have-
a) high input impedance
b) low input impedance
c) same input impedance
d) none
Answer is :- high input impedance

15. The source-drain channel of JFET is -
a) ohmic
b) bilateral
c) unilateral
d) both a and b
Answer is :- both a and b

16. diac is equivalent to a -
a) Pair of SCRs
b) Pair of four layer SCRs
c) Diode and two resistors
d) Triac width
Answer is :- Pair of four layer SCRs

17. When a sample of N type semiconductor has electron density of 6.25 1011 /cm3 at 300K and if the intrinsic concentration of carriers in this sample is 2.5 1013/cm3 then the hole density will be
a) 106/cm3
b) 103/ cm3
c) 1010/ cm3
d) 1012/ cm3
Answer is :- 103/ cm3

18. The statement In any network of linear impedances, the current flowing at any point is equal to the algebraic sum of the currents caused to flow at that point by each of the sources of emf taken separately with all other emfs reduced to zero represents -
a) Kirchhoffs law
b) Nortons theorem
c) Thevenins theorem
d) Superposition theorem
Answer is :- Superposition theorem

19. One of the following modes which has the characteristics of attenuation becoming less as the frequency is increased and is attractive at icrowave frequencies of circular cylindrical wave guides is
a) TE1 mode
b) TM01 mode
c) TE01 mode
d) Higher order mode
Answer is :- TE01 mode

20. A two-port network is symmetrical if
a) z11z22 z12z21 = 1
b) h11h22 h12h21 = 1
c) AD BC = 1
d) y11y22 y12y21 = 1
Answer is :-AD " BC = 1