T.(A) ΠD .T.2 ΤW (B) D2 W2 22IES-42. ANS. (B) SHEAR STRESS= ΤW= Τ ×...
2
.t.
(a)
π
d .t.
2
τ
w
(b)
d
2
w
2 2
2
IES-42. Ans. (b)
Shear stress
= τ
W
= τ × π
Shear fore
dt
= τ × π ×
=
π
τ
d
d
( )
Torque T
dt
.t
W
W
2
2
IES-43.
A circular solid rod of diameter d welded to a rigid flat plate by a circular
fillet weld of throat thickness t is subjected to a twisting moment T. The
maximum shear stress induced in the weld is
[IES-2003]
(a)
T
2
td
π
(b)
2T
2
π
(c)
4T
2
π
(d)
2T
3
π
⎛ ⎞
⎜ ⎟
T.
d
T.r
2
2T
τ =
=
⎝ ⎠
=
IES-43. Ans. (b)
3
2
J
td
td
π
π
4
IES-44.
The permissible stress in a filled weld is 100 N/mm
2
. The fillet weld has
equal leg lengths of 15 mm each. The allowable shearing load on weldment
per cm length of the weld is
[IES-1995]
Design of Joint
S K Mondal’s
Chapter 1
(a) 22.5 kN
(b) 15.0 kN
(c) 10.6 kN
(d) 7.5 kN.
IES-44. Ans. (c) Load allowed = 100 x 0.707 x 10 x15 = 10.6 kN
Threaded fasteners
IES-45.
A force ‘F’ is to be transmitted through a square-threaded power screw
into a nut. If ‘t’ is the height of the nut and ‘d’ is the minor diameter, then
which one of the following is the average shear stress over the screw
thread?
[IES 2007]
(a)
2f
π
dt
2 dt
π
(d)
4F
π
dt
(b)
F
π
dt
(c)
F
IES-45. Ans. (b)
IES-46. Consider the case of a square-
threaded screw loaded by a nut as
shown in the given figure. The
value of the average shearing
stress of the screw is given by
(symbols have the usual meaning)
2F
F
(a)
(b)
d h
d h
r
r
(c)
d
dh
dh
[IES-1997]
IES-46. Ans. (b)
IES-47.
Assertion (A): Uniform-strength bolts are used for resisting impact loads.
Reason (R): The area of cross-section of the threaded and unthreaded parts is
made equal.
[IES-1994]
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
IES-47. Ans. (c) A is true and R is false.
IES-48.
How can shock absorbing capacity of a bolt be increased? [IES 2007]
(a) By tightening it property
(b) By increasing the shank diameter
(c) By grinding the shank
(d) By making the shank diameter equal to the core diameter of thread
IES-48. Ans. (d)
IES-49.
The number of slots is a 25 mm castle nut is
[IES-1992]
(a) 2
(b) 4
(c) 6
(d) 8
IES-49. Ans. (c)
Design of Friction Drives
S K Mondal’s
Chapter 2