17929
11718
3 Hours / 100 Marks Seat No.
Instructions – (1) All Questions are Compulsory.
(2) Answer each next main Question on a new page.
(3) Illustrate your answers with neat sketches wherever
necessary.
(4) Figures to the right indicate full marks.
(5) Assume suitable data, if necessary.
(6) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(7) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
Marks
1. Attempt any TEN of the following: 20
a) Define an Ideal Machine.
b) Explain law of Machine? State its use.
c) Define Mechanical Advantage and Velocity Ratio.
d) State the principle of transmissibility of force.
e) Name the characteristics of a force.
f) State Varignon’s Theorem of moments.
g) State law of parallelogram of forces.
h) Explain Bow’s notation? Where it is used.
i) Define Free Body diagram with one example.
j) State Lami’s theorem.
k) State two types of beams with diagram.
P.T.O.
17929 [2]
Marks
l) Define angle of repose.
m) Show C.G. of a cone having base 100 mm and height 300 mm
with a neat sketch.
n) Differentiate between Centroid and C.G.
2. Attempt any FOUR of the following: 16
a) In a machine an effort of 2 N lift a load of 30 N. If the
effort lost due to friction is 0.5 N. Find V.R. and efficiency.
b) V.R. of a machine is 50 and the law of machine is
P = 0.033W + 20N . Find the maximum M.A. and maximum
efficiency of the machine. State whether it is reversible or not.
c) A simple screw Jack has thread of pitch 12 mm. Find the
effort required to lift the car load of 3 kN if the length of
handle is 500 mm and efficiency is 30%.
d) In a differential axle and wheel, the dia. of wheel is 400 mm
and dia. of axles are 100 mm and 80 mm. It an effort of 50 N
can lift a load of 1500 N, find V.R. and efficiency of the
machine.
e) In a single threaded worm and worm wheel, the number of
teeth on worm wheel are 50. The dia. of effort wheel is 20 cm,
and that of load drum is 10 cm find the effort required to lift a
load of 300 N at an efficiency of 20%.
f) State velocity ratio for single purchase crab and double
purchase crab and meaning of terms used.
3. Attempt any FOUR of the following: 16
a) State any four properties of couple.
b) A force of 80 N is acting on a body. Find its components
such that one component has an angle 45° and the other has
an angle of 30° on either side of force.
17929 [3]
Marks
c) Find the mutually perpendicular components of the following
forces all acting away from the point
(i) 100 N at 30° West of South
(ii) 400 N due North
(iii) 250 N North-East
(iv) 150 N due West
d) Calculate the magnitude and direction of resultant for concurrent
force system as shown in Figure No. 1.
Fig. No. 1
e) Forces of 2, 3, 4, 5 and 6 N respectively act at one of the
angular points of a regular hexagon towards the other five
angular points taken in to order find resultant of system.
f) Five parallel forces are acting on a beam as shown in
Figure No. 2. Find resultant in magnitude and direction and
locate its position w.r.t. 10 kN force.
Fig. No. 2
P.T.O.
17929 [4]
Marks
4. Attempt any FOUR of the following: 16
a) Find graphically the resultant of concurrent force system
shown in Figure No. 3.
Fig. No. 3
b) Find the resultant of parallel forces as shown in Figure No. 4
by graphical method.
Fig. No. 4
c) Forces of 2, 4, 6 and 8 kN resp. act on regular pentagon as
shown in Figure No. 5. Find magnitude and direction of
resultant force graphically.
Fig. No. 5
17929 [5]
Marks
d) A sphere weighing 500 N is supported by two planes. One
plane is vertical and other is inclined at 60° to the horizontal.
Calculate the reactions at the planes.
e) A ball weighing 150 N is suspended vertically by a string
attached to a ceiling. Find the magnitude of the force which
should be applied horizontally which will make the string
inclined at 120° to the direction of force. Also determine
tension in the string.
f) Find analytically the equilibrant of following concurrent force
system shown in Figure No. 6.
Fig. No. 6
5. Attempt any FOUR of the following: 16
a) A simply supported beam 8 m carries udl of 20 kN/m over
entier span and point load of 80 kN at 3 m from left support.
Find support reaction analytically.
b) Solve Que. 5(a) by graphical method.
c) State laws of static friction.
d) A body weighing 150 N is resting on a rough horizontal plane.
A pull of 30 N applied at 30° up the horizontal just moves the
body. Find the coefficient of friction.
e) A body of weight 300 N is placed on plane inclined at an
angle of 17° with the horizontal. If the coefficient of friction
is 0.3, find the value of the force to be applied parallel to the
plane just to move the body up the plane.
P.T.O.
17929 [6]
Marks
f) A beam AB of span 10 m is simply supported at its ends. It
carries point loads of 4 kN and 8 kN at 4 m and 6 m from
left support respectively. It also carries a UDL ‘W’ kN/m for
4 m from the right end. It the left end reaction is 20 kN, find.
‘W’ and reaction at the right support.
6. Attempt any FOUR of the following: 16
a) A body weighing 12 kN is lying on a horizontal plane for
which m = 0.7. Determine normal reaction, limiting force of
friction, horizontal force reqd. to move it and angle of friction.
b) Determine the position of centroid of an unequal angle section
with dimensions 200 mm × 150 mm × 10 mm. Longer leg is
vertical.
c) A retaining wall of height 5.2 m has one side vertical. The
top width is 0.8 m and bottom width is 3.2 m. Find centroid.
d) Find the centroid of an inverted ‘T’ section with Flange
60 mm × 10 mm and web 50 × 10 mm.
e) A solid cone of base dia. 40 cm and height 100 cm is welded
to a hemisphere of same diameter as shown in Figure No. 7
below. Find the C.G. of the solid composite.
Fig. No. 7
17929 [7]
Marks
f) A solid cone of height 40 cm is placed on a cube of side
20 cm as shown in figure No. 8. Locate the position of C.G.
w.r.t. tip of the cone.
Fig. No. 8
