A pneumatic controller that increases the pressure of its branch ...

[tiffannnnyyyyyy]

A pneumatic controller that increases the pressure of its branch line when air temperature in the conditioned
  space goes up is called a(n) _____.
 
  a. direct-acting thermostat
  b. reverse-acting thermostat
  c. graduate thermometer
  d. E-P relay

Question 2

Why is 24V used in control circuits?
 
  a. Components are easy to install.
  b. Alternating current is not needed.
  c. It allows battery back-up.
  d. Electric shocks are eliminated.

[millet]

Answer to Question 1

a

Answer to Question 2

a

[tiffannnnyyyyyy]

Thanks for the timely response, appreciate it

[sultana.d]

Wow, this really help