GATE Mechanical Engineering Fluid Mechanics Set 1

1. A body submerged in static fluid will undergo

(A) Longitudinal strain 

(B) Lateral strain
(C) Volumetric strain
(D) Zero Strain 
Ans: C: The pressure inside static fluid is same in all directions hence the body will undergo Volumetric strain


2. For water reservoir with pressure head of 500m which of the turbine is most suitable 
(A) Francis turbine
(B) Pelton wheel turbine
(C) Kaplan turbine
(D) None of the above

Ans: B: Pelton wheel turbine is suitable for high head water reservoir.

3. For steady laminar flow of s fluid between two plates, the velocity of fluid
(A) will be constant throughout the section.
(B) will be parabolic in nature.
(C) will be random through out the section
(D) None of the above

Ans: B: For steady laminar flow of s fluid between two plates, the velocity of fluid will be parabolic in nature.
            Maximum at the center and zero near the plates. 

4. Match the following 

1. Pelton wheel turbine            a. Medium Head  Medium Discharge
2. Francis turbine                    b. Low Head High Discharge
3. Kaplan turbine                     c. High Head Low Discharge

(A) 1-c, 2-a, 3-b
(B) 1-b, 2-a, 3-c
(C) 1-a, 2-b, 3-c
(D) 1-b, 2-a, 3-c

Ans: A: 1-c, 2-a, 3-b.


5. A Pitot tube converts
(A) pressure head to potential head.
(B) kinetic head to potential head.
(C) kinetic head to pressure head
(D) potential head to kinetic head

Ans: C: Pitot tube is used to measure the velocity of fluid in pipe which converts kinetic head to pressure head. 

GATE Mechanical Engineering Fluid Mechanics Set 2

GATE Mechanical Engineering Mathematics Set1

1. A Coin is tossed 4 times. What is the probability of getting heads exactly 3 times?

(A) 1/4
(B) 3/8
(C) 1/2
(D) 3/4
Ans: Option A :  when coin is tossed getting a Head H or Tail T has pobability = 1/2;
If the coin was tossed 4 times to get the Head H exactly 3 times there are four different ways
1: THHH : 1/2 * 1/2 * 1/2 * 1/2 = 1/16
2: HTHH : 1/2 * 1/2 * 1/2 * 1/2 = 1/16
3: HHTH : 1/2 * 1/2 * 1/2 * 1/2 = 1/16
4: HHHT : 1/2 * 1/2 * 1/2 * 1/2 = 1/16
as there are 4 different ways this result can be obtained hence the actual probability is
Ans = 1/16 + 1/16 + 1/16 + 1/16 = 1/4

2. The divergence of the vector field  (x-y)i  + (y-x)j + (x+y+z)k is
(A) 0
(B) 1
(C) 2
(D) 3

Ans: D : the divergence is given by:


3. If 3 coins are tossed simultaniously, the probability of getting atleast 1 Head is
(A) 1/8
(B) 3/8
(C) 1/2
(D) 7/8
Ans: D:
traditional solution:
The possible outcome when 3 coins are tossed are
TTT, HTT, THT, TTH, HHT, HTH, THH, HHH
We Need atleast 1 Head, there are 7 combinations out of 8 in which user will get atleast 1 Head
Hence answer is 7/8.

Quick Solution:
When single coin is tossed the probability of getting Head is 1/2.
When more than 1 coins are tossed and only one Head is expected then it is likely to occur more easily than when single coin is tossed. Hence the probability of getting atleast 1 Head when 3 coins are tossed is more than 1/2.
There is only one option out of four having value more than 1/2 is Option "D" i.e 7/8

4. For the given matrix find the value of ‘x’ if Transpose of the matrix is equal to Inverse of the Matrix.

(A) -4/5
(B) -3/5
(C) 3/5
(D) 4/5
Ans:  A:-4/5

5. The divergence of the vector field 3xz i + 2xy j – yz²  k at a point (1,1,1) is equal to
(A) 7
(B) 4
(C) 3
(D) 0

Ans: (C):3

GATE Mechanical Engineering Mathematics Set2

Sample Question Papers

This Blog will contain links for sample questions for various competitive exams like: GATE, CAT.

Check out following links:
GATE Mechanical Engineering Syllabus
GATE Mechanical Engineering Mechanics Set1
GATE Mechanical Engineering Mathematics Set1
GATE Mechanical Engineering Thermodynamics Set1
GATE Mechanical Engineering Fluid Mechanics Set1
GATE Mechanical Engineering Mechanics Set2
GATE Mechanical Engineering Mathematics Set2
GATE Mechanical Engineering Fluid Mechanics Set 2
GATE Mechanical Engineering Production Engg Set 1

GATE Mechanical Engineering Thermodynamics Set1

1. 2 moles of oxygen is mixed with isentropically with another 2 moles of oxygen, so that final pressure and
temperature becomes same as that of their individual constituents at initial stage. The universal gas constant is
given as R. the change of entropy per mole of oxygen is given by
(A) –Rln2
(B) 0
(C) Rln2
(D) Rln4
Ans B: for isentropic process the heat transfer is zero hence change in entropy is zero.
Isentropic means No Change in Entropy, hence in above question the answer is Zero.

2. If a closed system undergoes irreversible process, the Entropy of the system
(A) must increase
(B) always remains constant
(C) must decrease
(D) can increase, decrease or remain constant
Ans: A: irreversible process means increase in entropy hence answer is "A".

3. In an ideal vapour compression refrigeration cycle, the specific enthalpy of the refrigerent (kJ/kg) at different states are given as
Inlet of Condenser = 283
Exit of Condenser = 116
Exit of evaporator = 232
the COP of this cycle is
(A) 2.27
(B) 2.75
(C) 3.27
(D) 3.75
Ans: A:
Enthalpy @ exit of condenser = Enthalpy @ inlet of evaporator
Desired Output = Heat absorbed during Evaporation = Exit of evaporator - Exit of Condenser
Desired Output = 232-116 = 116 kJ/kg
Input to ref system = Workdone by compressor = Inlet of Condenser - Exit of evaporator
Input to ref system = 283-232 = 51 kJ/kg
COP = Desired Output/Input to ref system = 116/51 = 2.27

4. Which of the following statement is true for water. 
(A) Latent heat of vaporization decreases with increase in pressure and increase in temperature 
(B) Latent heat of vaporization decreases with increase in pressure and decrease in temperature
(C) Latent heat of vaporization decreases with decrease in pressure and increase in temperature
(D) Latent heat of vaporization decreases with decrease in pressure and decrease in temperature

Ans: A: Latent heat of vaporization decreases with increase in pressure and increase in temperature .

GATE Mechanical Engineering Mechanics Set1

1 As per Lami's theorom if  a body is in equilibrium under action of three forces, each force is proportional to
A) Sine of angle between other two forces.
B) Cosine of angle between other two forces.
C) Tan of angle between other two forces.
D) Non of above.

ANS: A) Sine of angle between other two forces.

2. In a perfect load bearing frame what is the necessary condition:
A) m =  2 j +3
B) m =  2 j -3

C) m =  j
D) j =  2 m +3
where m = no of members
          j = no of joints
ANS: B) m =  2 j -3

3. In Static friction
A) Force of friction acts in opposite direction of that in which body tends to move.
B) The force of friction bears a constant ratio to Normal Reaction between two surfaces.
C) Force of friction depends upon roughness/smoothness of surfaces.
D) All of above.

ANS: D) All of above.


4. In Space, when one body sides over another body the force of friction will be
A) m1*g
B) m2*g

C) (m1 + m2)*g
D) 0

ANS: D) 0. As in space the gravity does not exist the Normal reaction between two surfaces will be 0 hence the force of friction will be zero.

5. In a machine what does Mechanical Advantage / Velocity Ratios signify
A) Effort required (P) to lift load (W).
B) Efficiency of the machine
C) Reversibility or Irreversibility of machine
D) None of above.
ANS: B) Efficiency of the machine


GATE Mechanical Engineering Mechanics Set 2