Question

Fill in the blanks :

An electron emitter must have ...................... work function and .................... melting point.

• A. high, high
  
• B. low, low
  
• C. high, low
  
• D. low, high
  

Answer 1

The correct option is D low, high

The work function should be low, so that electron is emitted even when it is heated at low temperatures.

The melting point should be high, so that it does not melt when heated.