Basic Electrical Mcqs

The ratio of mass of proton to that of electron is nearly_____________?

A. 1840
B. 1840
C. 30
D. 4

Voltage dependent resistors are used_____________?

A. for inductive circuits
B. to supress surges
C. as heating elements
D. as current stabilizers

A. Charcoal
B. Silicon Carbide
C. Nichrome
D. Graphite

All good conductors have high____________?

A. conductance
B. resistance
C. reluctance
D. thermal conductivity

are the materials having electrical conductivity much less than most of the metals but much greater than that of typical insulators______________?

A. Varistors
B. Thermistor
C. Semi-conductors
D. Variable resistors

An open resistor, when checked with an ohm-meter reads_____________?

A. zero
B. infinite
C. high but within tolerance
D. low but not zero

A rheostat differs from potentiometer in the respect that it_____________?

A. has lower wattage rating
B. has higher wattage rating
C. has large number of turns
D. offers large number of tapg

Which of the following statement is correct_______________?

A. A semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator
B. A semi-conductor is a material which has conductivity having average value of conductivity of metal and insulator
C. A semi-conductor is one which con¬ducts only half of the applied voltage
D. A semi-conductor is a material made of alternate layers of conducting material and insulator

The condition for the validity under Ohm’s law is that_______________?

A. resistance must be uniform
B. current should be proportional to the size of the resistance
C. resistance must be wire wound type
D. temperature at positive end should be more than the temperature at negative end

When current flows through heater coil it glows but supply wiring does not glow because______________?

A. current through supply line flows at slower speed
B. supply wiring is covered with insulation layer
C. resistance of heater coil is more than the supply wires
D. supply wires are made of superior material