SECOND SESSIONAL TEST (odd SEMESTER 2009-10)
B.Tech…first Semester
Sub Name: Engineering
Mechanics Max.
Marks: 30
Sub Code: EME-201 Max.
Time: 2: 00 Hr
Group A
Q.1 Choose the correct answer
of the following questions 1x6=6
(i) If two forces of equal
magnitudes have a resultant force of the same magnitude then the angle between them
is
(a) 00 (b) 900 (c) 1200 (d) 1350
Ans: ( c)
Explanation: P2 = P2 + P2 +2P.P.cos
θ
ð
P²= P² (1+2cos θ)
ð
cos θ = -½
ð
θ = 120°
(ii) If a ladder is kept at
rest on a vertical wall making an angle θ with horizontal. If co-efficient of
the friction in all the surfaces be µ, then the tangent of the angle θ will be
equal to
(a) (1-µ2)/2µ (b) (1-µ)2 /2µ
(c) (1-µ)/2µ
(d) none of the above
Explanation: (a) (1-µ2)/2µ
(iv) Varignon’s theorem is
related with _____________ .
Answer: moment
(v) If two forces of equal
magnitudes P having an angle (90°- θ) between them, then their resultant force
will be equal to ________.
Answer: √2P (1+sin θ)
(vi) A fixed joint produces
(a) 1
(b) 2
(c)
3
(d) 4 reactions
Answer: (c ) 3
(vii) The equilibrium
conditions of concurrent force system is_________.
Answer: ∑Fx =0; ∑Fy=0.
Group B
8x3=24
Attempt any three questions
Q.2. State and explain
Varignon’s theorem of moment. Three forces of magnitudes 3 KN, 4 KN and 2KN act
along the three side of an equilateral triangle ∆ABC in order. Find the
position, direction and magnitude of the resultant force. 4+4
Answer: resultant force: √3
KN
Q.3 (a) Two cylindrical
rollers are kept at equilibrium inside a jar or channel as shown in the figure.
The channel width is 1000 mm, where as the rollers have diameters 600 mm and
800 mm respectively. The weights are 2 kN and 5 kN respectively. Find all the
reactions at contacts.
4+4
(b) What is pure bending? If
a stone is thrown with a velocity 400 m/s then find the maximum height that the
stone can reach.
Q:4) a) Classify different types of
joints in beam with proper explanations.
(b) Find the reactions at the
support for the beam as shown in the figure. 4+4
