Applied Mechanics and Design - Online Test
Q1. The spring constant of a helical compression spring DOES NOT
depend on
Answer : Option B
Explaination / Solution:
The spring constant (k) for the compression helical spring is given
by,
So, K is dependent on wire diameter, number of active coils, modulus
of rigidity, coil diameter, but does not depends on the martial
strength.
Q2. A two-member truss PQR is supporting a load W. The axial
forces in members PQ and QR are respectively
Answer : Option B
Explaination / Solution:
FBD for the point Q is given by,
Q3. In the gear train shown, gear 3 is carried on arm 5. Gear 3
meshes with gear 2 and gear 4. The number of teeth on gear 2, 3, and
4 are 60, 20, and 100, respectively. If gear 2 is fixed and gear 4
rotates with an angular velocity of 100 rpm in the counter clockwise
direction, the angular speed of arm 5 (in rpm) is
Answer : Option C
Explaination / Solution:
Given (taking CW as positive)
Q4. A solid disc with radius a is connected to a spring at a point d
above the center of the disc. The other end of the spring is fixed to the
vertical wall. The disc is free to roll without slipping on the ground.
The mass of the disc is M and the spring constant is K. The polar
moment of inertia for the disc about its center is j = Ma2/2
The natural frequency of this system in rad/s is given by
Answer : Option C
Explaination / Solution:
No Explaination.
Q5. A link OB is rotating with a constant angular velocity of 2 rad/s in counter clockwise direction and a block is sliding radially outward on it with an uniform velocity of 0.75 m/s with respect to the rod, as shown in the figure below. If OA = 1m, the magnitude of the absolute acceleration of the block at location A in m/ S2 is
Answer : Option C
Explaination / Solution:
Q6. The principal stresses at a point inside a solid object are Ο1 =
100 MPa, Ο2 = 100 MPa and Ο3 = 0MPa. The yield strength of the
material is 200 MPa. The factor of safety calculated using Tresca
(maximum shear stress) theory is nT and the factor of safety
calculated using von Mises (maximum distortional energy) theory is
nV. Which one of the following relations is TRUE?
Answer : Option A
Explaination / Solution:
No Explaination.
Q7. The tool life equation for HSS tool is ππ0.14π0.7π0.4 = Constant.
The tool life (T) of 30 min is obtained using the following cutting
conditions:
V = 45 m/min, f = 0.35 mm, d = 2.0 mm
If speed (V), feed (f) and depth of cut (d) are increased individually
by 25%, the tool life (in min) is
Answer : Option B
Explaination / Solution:
Given tool lite equation
ππ0.14π0.7π0.4 = C
T = 30 min
And V = 45 m/min, f = 0.35 mm, d = 2.0 mm
After increasing 25%, we get
vβ = 56.25 m/min,
fβ = 0.4375 mm
dβ= 2.5 mm
Q8. A cylindrical job with diameter of 200 mm and height of 100
mm is to be cast using modulus method of riser design. Assume that
the bottom surface of cylindrical riser does not contribute as cooling
surface. If the diameter of the riser is equal to its height, then the
height of the riser (in mm) is
Answer : Option A
Explaination / Solution:
Given that 
for casting dc = 200 mm, hc = 100 mm
for river dr = hr
According to modules method
Q9. A long thin walled cylindrical shell, closed at both ends, is subjected to an internal pressure. The ratio of the hoop stress (circumferential stress) to longitudinal stress developed in the shell is
Answer : Option C
Explaination / Solution:
Q10. Which one of the following types of stress-strain relationship best describes the behavior of
brittle materials, such as ceramics and thermosetting plastics, (Ο = stress and Ξ΅ = strain)?
Answer : Option D
Explaination / Solution:
No Explaination.
