BSNL Placement Papers

If the voltage applied across a capacitance is triangular in waveform then the waveform of the current is-
a) Triangular

b) Trapezoidal

c)) Sinusoidal

d) Rectangular

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)) It’s value for all substances is less than one

d)) None

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

For small size, high frequency coils, the most common core material is

a) Air

b) Ferrite

c) Powdered ion

d) Steel

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

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 value

When a semiconductor based temperature transducer has a temperature coefficient of â€"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

The location of lightning arrestor is -

a) Near the transformer

b) Near the circuit breaker

c) Away from the transformer

d) None

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