Mechanical Engineering Mcqs

Water at pressure of 4 kg/cm2 and 160°C temperature when exposed to atmosphere will_________________?

(A) boil

(B) flash i.e. get converted into steam

(C) remain as it was

(D) cool down

(D) none of the above

Submitted By: Ali Uppal


In a throttling process________________?

(A) steam temperature remaisn constant

(B) steam pressure remains constant

(C) steam enthalpy remains constant

(D) steam entropy remains constant

(D) steam volume remains constant

Submitted By: Ali Uppal


The pressure at which latent heat of vaporisation of water is zero, is_________________?

(A) below atmospheric pressure

(B) 1 kg/cm2

(C) 100 kg/cm2

(D) 170 kg/cm2

(D) 225.6 kg/cm2

Submitted By: Ali Uppal


The latent heat of steam with increase of pressure__________________?

(A) remains same

(B) increases

(C) decreases

(D) behaves unpredictably

(D) none of the above

Submitted By: Ali Uppal


At which pressure the properties of water and steam become identical_________________?

(A) 0.1 kg/cm2

(B) 1 kg/cm2

(C) 100 kg/cm2

(D) 225.6 kg/cm2

(D) it is never possible

Submitted By: Ali Uppal


While steam expands in turbines, theoretically the entropy________________?

(A) remains constant

(B) increases

(C) decreases

(D) behaves unpredictably

(D) none of the above

Submitted By: Ali Uppal


Adiabatic process is________________?

(A) essentially an isentropic process

(B) non-heat transfer process

(C) reversible process

(D) constant temperature process

(D) constant enthalpy process

Submitted By: Ali Uppal


Pick up the wrong statement about critical condition of steam___________________?

(A) latent heat is zero

(B) liquid directly becomes steam

(C) specific volume of steam and liquid is same

(D) this is the maximum pressure limit

(D) all properties of liquid and steam are same

Submitted By: Ali Uppal


Pick up the wrong statement about water tube boiler in comparison to fire tube boilers ______________________?

(A) former generates steam at high pressure

(B) former occupies less space for same power

(C) rate of steam flow is more in former case

(D) former is used for high installed capacity

(D) chances of explosion are less in former case

Submitted By: Ali Uppal


A fusible plug is fitted in small boilers in order to ___________________?

(A) avoid excessive build up of pressure

(B) avoid explosion

(C) extinguish fire if water level in the boiler falls below alarming limit

(D) control steam dome

(D) remove molten aslj

Submitted By: Ali Uppal