The condensing pressure due to the presence of non-condensable gases, as compared to that actually required for condensing temperatures without non-condensable gases ____________________ ?

Related Mcqs:

1. A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure of about 67 kg/cm. The refrigerant used is________________?

   A. Ammonia
   B. Carbon dioxide
   C. Freon
   D. Brine
   E. Hydrocarbon refrigerant

2. Condensing temperature in a refrigerator is the temperature_________________?

   A. of cooling medium
   B. of freezing zone
   C. of evaporator
   D. at which refrigerant gas becomes liquid
   E. condensing temperature of ice

3. At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant_________________?

   A. decreases
   B. increases
   C. remains same
   D. depends on other factors
   E. none of the above

4. Allowable pressure on high-pressure side or ammonia absorption system is of the order of_________________?

   A. atmospheric pressure
   B. slightly above atmospheric pressure
   C. 2-4 bars
   D. 5-6 bars
   E. 7-10 bars

5. Presence of moisture in a refrigerant affects the working of___________________?

   A. compressor
   B. condenser
   C. evaparator
   D. expansion valve
   E. heat transfer

6. In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is_____________________?

   A. less than 2 kg
   B. more than or equal to 3.65 kg
   C. more than 10 kg
   D. there is no such consideration
   E. pone of the above

7. Cooling water is required for following equipment in ammonia absorption plant__________________?

   A. condenser
   B. evaporator
   C. absorber
   D. condenser and absorber
   E. condenser, absorber and separator (rectifier)

8. If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be________________?

   A. same
   B. more
   C. less
   D. more/less depending on rating
   E. unpredictable

9. The refrigeration effect in a dry evaporator compared to flooded evaporator in a similar plant is_________________?

   A. same
   B. more
   C. less
   D. more or less depending on ambient conditions
   E. unpredictable

10. The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P_____________________?

    A. more
    B. less
    C. equally.
    D. unpredictable
    E. none of the above