BSNL JTO (CE) Paper 2007 with Solutions Explanations at doorsteptutor. Com Part 2

Download PDF of This Page (Size: 149K)

16. The advantage of a semiconductor strain gauge cover the wire round strain gauge is that

(A) It is more sensitive

(B) It is more linear

(C) It is less temperature dependent

(D) Its cost is low

17. Barrier potential in a P - N junction is caused by

(A) Thermally generated electrons and holes

(B) Diffusion of majority carriers across the junction

(C) Migration of minority carriers across the junction

(D) Flow of drift current

18. When an NPN transistor is properly biased then most of the electrons from the emitter

(A) Recombine with holes in the base

(B) Recombine in the emitter itself

(C) Pass through the base to the collector

(D) Are stopped by the junction barrier

19. The depletion voltage for silicon diode at biases is

(A)

(B)

(C)

(D)

20. A UJT can

(A) Be triggered by any one of its three terminals

(B) Not be triggered

(C) Be triggered by two of its three terminals only

(D) Be triggered by all of its terminals only

21. The energy of electric field due to a spherical charge distribution of radius and inform charge density in vacuum is

(A)

(B)

(C)

(D)

22. Maxwell’s divergence equation for the magnetic field is given by

(A)

(B)

(C)

(D)

23. When a short grounded vertical antenna has a length which is at frequency f and if it's radiation resistances at is Ohms, then its radiation resistance at a frequency will be

(A) ohms

(B) ohms

(C) ohms

(D) ohms

24. In a cylindrical cavity resonator, the two modes which are degenerate would include

(A)

(B)

(C)

(D)

25. When an antenna of input resistance is connected to a line and if the losses are ignored then its efficiency will be nearly

(A)

(B)

(C)

(D)

26. The transformer utilization factor of full wave bridge rectifier is

(A)

(B)

(C)

(D)

27. When a dominant mode wave guide not terminated in its characteristic impedance is excited with a signal then if d is the distance between two successive minima of the standing wave in the

(A) An output power which is one - quarter of the input power

(B) An output power which is one - half of the input power

(C) An output voltage which is of the input voltage

(D) An output power which is of the input power.

29. While transporting a sensitive galvanometer

(A) The terminals are kept shorted

(B) Critical damping resistance is connected across the terminals

(C) The terminals are kept open circuited

(D) It does not matter as to what is connected across the terminals.

30. A T type attenuator is designed for an attenuation of and terminating resistance of . Which of the following values represent full series arm and shunt arm ?

1.

2.

3.

4.

(A) 1 and 3

(B) 1 and 4

(C) 2 and 3

(D) 2 and 4