When an electric field acts on the electrons in a conductor, it does not produce a net acceleration. This happens because the electrons keep on colliding with the atoms that make up the conductor. Thus the electrons acquire a constant average
Velocity
Speed
Drift speed
Escape velocity
In laboratory, Wheatstone bridge is used for the measurement of
Inductance
Capacitance
Resistance
None of the above
In a Wheatstone bridge, which of the following expressions is correct at balanced condition? (where, R1 and R2 are ratio arms, R3 is the known variable resistance and R4 is the unknown resistance.)
R1/R2 = R3/R4
R1/R4 = R3/R2
R1/R4 = R2/R3
R1/R2 = R3/R4
What the increase in temperature, the resistivity of all metallic conductors
Increases
Decreases
Remains constant
Sometimes increases and sometimes decreases
Which of the following metals has the lowest resistivity at room temperature?
Silver
Copper
Aluminium
Gold
With increasing temperature, the resistivity of a semi-conductor
Decreases very rapidly
Increases very rapidly
Remains at a constant value
Increases very slowly
Which of the following metals is the best electrical conductor at room temperature?
Aluminium
Copper
Gold
Iron
Which of the following alloys has the highest conductivity at room temperature?
Brass
Constanton
Manganin
Nichrome
The times required for the charge given to a conducting body to redistribute itself in such a way that a zero electric field exists within and tangentially to the conductor surface is called
Charge relaxation times
Charge build-up time
Charge annihilation time
None of the above
The temperature, at which the resistivity of a super conductor plunges to zero is called
Ambient temperature
Critical temperature
Threshold temperature
None of the above