Mechanical Engineering - Online Test
Q1. In a steady flow through a nozzle, the flow velocity on the nozzle axis is given
by v = u0(1 + 3x/L), where
x is the distance along the axis of the nozzle from its
inlet plane and
L is the length of the nozzle. The time required for a fluid particle
on the axis to travel from the inlet to the exit plane of the nozzle is
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. The 4-point Discrete Fourier Transform (DFT) of a discrete time sequence {1,0,2,3} is
Answer : Option D
Explaination / Solution:
Q3. A mass m attached to a spring is subjected to a harmonic force as shown in
figure. The amplitude of the forced motion is observed to be 50mm. the value of
m (in kg) is
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. Consider steady laminar incompressible anti-symmetric fully developed viscous
flow through a straight circular pipe of constant cross-sectional area at a Reynolds
number of 5. The ratio of inertia force to viscous force on a fluid particle is
Answer : Option A
Explaination / Solution:
No Explaination.
Q5. The Taylor series expansion of 3 sin x + 2 cos x is
Answer : Option A
Explaination / Solution:
Given the function
f(x) = 3 sin x + 2 cos x
Now, we have the Taylor’s expansion for the trigonometric function as
Substituting it in equation (1), we get
Q6. For the epicyclic gear arrangement shown in the figure, ω2 = 100rad / s clockwise
(CW) and ωarm = 80rad / s counter clockwise (CCW). The angular velocity ω5 (in rad/s) is
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. A steel rod of length L and diameter D, fixed at both ends, is uniformly heated to a temperature rise of ΔT . The Young’s modulus is E and the co-efficient of linear expansion is α. The thermal stress in the rod is
Answer : Option C
Explaination / Solution:
No Explaination.
Q8. For a function g (t), it is given that 
for any real value 𝜔. If 
is
for any real value 𝜔. If is
Answer : Option B
Explaination / Solution:
Given the relations
The Fourier transformation of f (t) is defined as
Now, from equation (2), we have
where u (t) is unit step function. Taking Fourier transform both the sides, we have
Q9. A lightly loaded full journal bearing has a journal of 50mm, bush bore of
50.05mm and bush length of 20mm. if rotational speed of journal is 1200rpm
and average viscosity of liquid lubricant is 0.03 Pa s, the power loss (in W) will be
Answer : Option A
Explaination / Solution:
No Explaination.
Q10. For an under damped harmonic oscillator, resonance
Answer : Option C
Explaination / Solution:
No Explaination.
