MCQ
3801. The center of gravity of a T-section 100mm x 150mm x 50mm from its bottom is-
50mm
75mm
87.5mm
125mm
ব্যাখ্যা: [Note]: ¯x=a₁ x₁ + a₂ x₂ /a₁ + a₂
=(100x50x125) + (50×100×50) / (100x50) + (50x100) = 87.5
3802. If the resultant of two force P & Q acting at an angle θ, makes an angle α with force P, then-
tanα = P sinθ / P+Q cosθ
tanα = P cosθ / P+Q cosθ
tanα = Q sinθ / P+Q cosθ
3803. The resultant of two force P & Q acting at an angle θ is-
√P^2+Q^2+2PQsinθ
√P^2+Q^2+2PQcosθ
√P^2+Q^2-2PQcosθ
3804. The rate of change of displacement of a body is called
velocity
momentum
acceleration
none of these
3805. The moment of inertia of a square of side a about an axis through its centre of gravity is-
a^4 /4
a^4 /8
a^4 /12
a^4 /36
3806. A framed structure is imperfect, if the number of members are ---(2j-3).
equal to
less than
greater than
either b or c
3807. A smooth cylinder lying on its convex surface remains in- equilibrium.
stable
neutral
unstable
none of these
3808. The minimum force required to slide a body of weight W on a rough horizontal plane is-
W sineθ
W coseθ
W tanθ
none of these
3809. The friction experienced by a body, when at rest, is known as-
static friction
dynamic friction
limiting friction
coefficient of friction
3810. The center of gravity of a right circular solid cone is at a distance of---- from its base, measured along the vertical axis.
h/2
h/3
h/4
h/6
3811. A force acting in the opposite direction to the motion of the body is called force of friction.
Agree
Disagree
3812. The friction experienced by a body, when in motion, is known as-
rolling friction
static friction
limiting friction
dynamic friction
3813. The center of gravity of a semi-circle lies at a distance of ----from its base measured along the vertical radius. 8r
3r/8
3r/4π
4r/3π
8r/3
3814. A redundant frame is also called- frame.
imperfect
deficient
perfect
3815. Moment of inertia of a circular section about an axis perpendicular to the section is-
πd³/16
πd³/32
πd^4/64
πd^4/32
ব্যাখ্যা: Izz = Ixx + Iyy = πd^2 /32
3816. The terms 'leverage' & 'mechanical advantage' of a compound lever have got same meaning-----
Right
Wrong
3817. Which of the following is a scalar quantity?
Force
Acceleration
Speed
Velocity
3818. An irregular body may have more than one centre of gravity.....
Yes
No
3819. The slope of a stress-strain curve in the elastic deformation region is-
elastic modulus
plastic modulus
poison's ratio
none of the above
3820. If the resultant of a number of forces acting on a body is 0. Then the body will be equilibrium........
Yes
No