Electrical Engineering Mcqs

The electrical conductivity of metals is typically of the order of (in Ohm-1m-1 )

A) 10⁷

B) 10⁵

C) 10^-4

D) 10^-6

Two wires A and B of the same material and length l and 2I have radius r and 2r respectively. The ratio of their specific resistance will be

A) 1 : 1

B) 1 : 2

C) 1 : 4

D) 1 : 8

For a fixed supply voltage the current flowing through a conductor will increase when its

A) Area of x-section is reduced

B) Length is reduced

C) Length is increased

D) Length is increased and x-sectional area is reduced

Which of the following statements is correct regarding resistance?

A) The resistance of a conductor is the hindrance by which the conductor opposes the flow of current through it

B) The resistance of wire is independent of the temperature for most of the materials

C) The resistance of a wire does not depend upon its material

D) None of the above

Ohm’s law is applicable to

A) Semiconductors

B) Vacuum tubes

C) Electrolytes

D) None of these

The condition for the validity of Ohm’s law is that the

A) Temperanirc should remain constant

B) Current should be proportional to voltage

C) resistance must be wire wound type

D) all of the above

Correct form of Ohm’s law

A) 1= VR

B) V ∞I

C) V=1R

D) All of the above

The draft velocity of electrons is

A) Larger than speed of light

B) almost equal to speed of light

C) Equal to speed of light

D) Very small in comparison to speed of light

Current velocity through a copper conductor is

A) Nearly 3 x10⁹m/s

B) Of the order of a few um/s

C) Independent of current strength

D) The same as propagation velocity of electric energy

The minimum requirements for causing flow of current are

A) A voltage source, a resistor and a switch

B) A voltage source and a conductor

C) A power source and a bulb

D) A voltage source, a conductor, an ammeter and a switch