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

• 1. current through supply line flows at slower speed
• 2. supply wiring is covered with insulation layer
• 3. resistance of heater coil is more than the supply wires
• 4. supply wires are made of superior material

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

• 1. resistance must be uniform
• 2. current should be proportional to the size of the resistance
• 3. resistance must be wire wound type
• 4. temperature at positive end should be more than the temperature at negative end

Question: Which of the following statement is correct_______________?

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

Question: A rheostat differs from potentiometer in the respect that it_____________?

• 1. has lower wattage rating
• 2. has higher wattage rating
• 3. has large number of turns
• 4. offers large number of tapping

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

• 1. zero
• 2. infinite
• 3. high but within tolerance
• 4. low but not zero

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

• 1. Varistors
• 2. Thermistor
• 3. Semi-conductors
• 4. Variable resistors

Question: All good conductors have high____________?

• 1. conductance
• 2. resistance
• 3. reluctance
• 4. thermal conductivity

Question: Voltage dependent resistors are usually made from________________?

• 1. Charcoal
• 2. Silicon Carbide
• 3. Nichrome
• 4. Graphite

Question: Voltage dependent resistors are used_____________?

• 1. for inductive circuits
• 2. to supress surges
• 3. as heating elements
• 4. as current stabilizers

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

• 1. 1840
• 2. 1840
• 3. 30
• 4. 4