Q261.Three forces are acting at a point in a plane, The angle between P and Q is 150o and the angle between Q and R is 120o. In equilibrium, the ratio of force P,Q, R will be–
Correct answer: 3: 2: 1
Q262.The resultant of two equal forces is equal to either of them. The angle between the forces is–
Correct answer: 120o
Q263.The resultant of the forces acting on the side BC, CA and AB of a triangle ABC Passes through the center of circumference of the triangle is–
Correct answer: P cosA +QcosB+RcosC= 0
Q264.The two identical spheres made of same materials of radius 6 cm and 3 cm respectively joined together. At what distance will the center of gravity of the whole system be from the center of the larger sphere?
Correct answer: 1 cm
Q265.If the interior center of ∆ ∆ ∆ABC is 'I', and the lengths of sides BC, CA and AB area a, b, c respectively then the value of aIA bIB cIC + + Will be–
Correct answer: 0
Q266.A body is free to slide on a smooth vertical circular wire and is connected by a string, equal in length to the radius of the circle, to the highest point of the circle. The tension T of the string equals:
Correct answer: the weight of the body
Q267.If a central orbit is the lemniscate of Bernoulli r2 = a2 cos 2θ, then the law of force is:
Correct answer: 7 1 F r ∝
Q268.A particle possesses two simple harmonic motions in perpendicular directions, having the same period, but differing in phase and amplitude. The particle describes:
Correct answer: an ellipse
Q269.The chord of curvature, through the pole of the equiangular spiral r = aemθ is–
Correct answer: 2r
Q270.The equations of the inverted cycloid is–
Correct answer: x a( sin )/y a(1 cos )
Q271.A particle is projected with velocity u making an angle α with the horizontal. The maximum horizontal is–
Correct answer: g 2 u
Q272.The coefficient of friction is equal to–
Correct answer: tangent of the angle of friction
Q273.The resultant of two forces P and Q is R, if Q is doubled, R is doubled; and if Q is reversed, R is again doubled. If the ratio 2 2 2 P: Q: R 2: 3: x, then x is equal to–
Correct answer: 2
Q274.The equation of the line of action of the single resultant of a system of coplanar forces is–
Correct answer: xY yX G
Q275.The distance from the base, of the central of gravity, of a solid right circular cone of uniform density and height 12cm is–
Correct answer: 3 cm
Q276.If the reaction R = 5 Newton and the forced friction 5 3 R 3 Newton then the angle of frictions is–
Correct answer: 6
Q277.The product of mass and acceleration is called:
Correct answer: Force
Q278.If a particle moves in a plance curve r = f (θ) then the radial acceleration is equal to–
Correct answer: 2 d r d r dt
Q279.The moment of inertia of a hollow sphere about a diameter is:
Correct answer: none of these
Q280.The maximum range, in a horizontal plane, of a projectile with a given velocity of projection is obtained if the angle of projection is–
Correct answer: 4