GuruMCQs.com provides all updated Mechanical Engineering Multiple Choice Questions (MCQs). The most frequently repeated mechanical MCQs section is frequently encountered in FPSC, PPSC, ETEA, NTS, Army, Navy, Air Force, educators, and various other competitive exams, as well as government and private job assessments. Most repeated mechanical engineering MCQs cover topics like Engineering Materials, Fluid Mechanics, Hydraulic Machines, Machine Design, Engineering Mechanics, Nuclear Power Plants, Steam Boilers, Engines, Nozzles, Turbines, Compressors, Gas Turbines, Jet Engines, Thermodynamics, Engineering Metrology, Heat Transfer, etc. Preparing with these MCQs can significantly contribute to your success in government job exams and interviews. Whether you are aiming to establish a career in engineering or seeking to enhance your existing skills, the Mechanical Engineering MCQs at www.gurumcqs.com serve as a valuable resource. Stay committed to regular practice and empower yourself with the knowledge needed to excel in your academic and professional endeavors.

**191. In vapour compression cycle using NH3 as refrigerant, initial charge is filled at:**
– A. suction of compressor
– B. delivery of compressor
– **C. high pressure side close to receiver**
– D. low pressure side near receiver
– E. anywhere in the cycle

**192. On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process:**
– A. involves no change in volume
– **B. takes place at constant temperature**
– C. takes place at constant entropy
– D. takes place at constant enthalpy
– E. takes place at constant pressure

**193. The leaks in a refrigeration system using Freon are detected by:**
– **A. halide torch which on detection produces greenish flame lighting**
– B. sulphur sticks which on detection gives white smoke
– C. using reagents
– D. smelling
– E. sensing reduction in pressure

**194. Moisture in freon refrigeration system causes:**
– A. ineffective refrigeration
– B. high power consumption
– **C. freezing automatic regulating valve**
– D. corrosion of whole system
– E. breakdown of refrigerant

**195. Superheating in a refrigeration cycle:**
– A. increases COP
– **B. decreases COP**
– C. COP remains unaltered
– D. other factors decide COP
– E. unpredictable

**196. For obtaining high COP, the pressure range of compressor should be:**
– A. high
– B. low
– **C. optimum**
– D. any value
– E. there is no such criterion

**197. The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will:**
– **A. increase**
– B. decrease
– C. remain unaffected
– D. may increase or decrease depending on the type of refrigerant used
– E. unpredictable