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 tapping

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

Temperature co-efficient of resistance is expressed in terms of___________?

A. Ohms/°c
B. Mhos/ohm°c
C. Ohms/ohm°c
D. Mhos/°c

Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be_____________?

A. 160 ohms
B. 80 ohms
C. 20 ohms
D. 10 ohms

Ohm’s law is not applicable to__________?

A. Semi-conductors
B. D. c. circuits
C. Small resistors
D. High currents