Question: If the resistance of a conductor does not vary in accordance with Ohm’s law it is known as____________?

• 1. non-linear conductor
• 2. reverse conductor
• 3. bad-conductor
• 4. non-conductor

Question: The forbidden gap in an insulator is________________?

• 1. large
• 2. small
• 3. nil
• 4. any of the above

Question: Effect of moisture on the insulating materials is to________________?

• 1. decrease dielectric constant
• 2. decrease dielectric strength
• 3. decrease insulation resistance
• 4. all of the above

Question: In conductors conduction of electricity takes place due to movement of_______________?

• 1. electrons only
• 2. positive ions only
• 3. negative ions only
• 4. positive and negative ions

Question: Surface resistance of an insulating material is reduced due to the______________?

• 1. smoky and dirty atmosphere
• 2. humidity in the atmosphere
• 3. both (A) and (b)
• 4. neither (A) nor (b)

Question: Which of the following factors affect resistivity of metals ?

• 1. Age hardening
• 2. Alloying
• 3. Temperature
• 4. All of the above

Question: Superconducting metal in super conducting state has relative permeability of________________?

• 1. zero
• 2. one
• 3. negative
• 4. more than one

Question: For a particular material the Hall coefficient was found to be zero. The material is______________?

• 1. insulator
• 2. metal
• 3. intrinsic semiconductor
• 4. none of the above

Question: For a hole which of the following statements is incorrect ?

• 1. Holes can exist in certain semiconductors only
• 2. Holes can exist in any material including conductors
• 3. Holes may constitute an electric current
• 4. Holes can be considered as a net positive charge

Question: The carbon percentage is least in__________________?

• 1. low carbon steel
• 2. wrought iron
• 3. cast iron
• 4. malleable iron