Question: In resistance heating highest working temperature is obtained from heating elements made of_____________?

• 1. nickel copper
• 2. nichrome
• 3. silicon carbide
• 4. silver

Question: For heating element high resistivity material is chosen to______________?

• 1. reduce the length of heating element
• 2. increase the life of the heating element
• 3. reduce the effect of oxidation
• 4. produce large amount of heat

Question: In the indirect resistance heating method, maximum heat-transfer takes place by____________?

• 1. radiation
• 2. convection
• 3. conduction
• 4. any of the above

Question: For intermittent work which of the following furnaces is suitable ?

• 1. Indirect arc furnace
• 2. Core less furnace
• 3. Either of the above
• 4. None of the above

Question: Induction heating takes place it which of the following ?

• 1. Insulating materials
• 2. Conducting materials which are magnetic
• 3. Conducting materials which are non-magnetic
• 4. Conducting materials which may or may not be magnetic

Question: By which of the following methods the temperature inside arc nace can be varied ?

• 1. By disconnecting some of the heating elements
• 2. By varying the operating voltage
• 3. By varying the current through heating elements
• 4. By any of the above method

Question: In induction heating ___________ is abnormally high?

• 1. phase angle
• 2. frequency
• 3. current
• 4. voltage

Question: In a resistance furnace the atmosphere is_____________?

• 1. oxidizing
• 2. deoxidising
• 3. reducing
• 4. neutral

Question: Which of the following has the highest value of thermal conductivity ?

• 1. Water
• 2. Steam
• 3. Sold ice
• 4. Melting ice

Question: Heat transfer by condition will not occur when____________?

• 1. bodies are kept in vacuum
• 2. bodies are immersed in water
• 3. bodies are exposed to thermal radiations
• 4. temperatures of the two bodies are identical