(a) Zero (b) Infinite (c) Between 0 and ∞ (d) Can not be determined Ans. a (13)
A solid sphere rolls down an inclined plane and its velocity at the bottom is v1. Then same sphere slides down the plane (without friction) and let its velocity at the bottom be v2. Which of the following relation is …
(a) 1.4 m/sec (b) 0.14 m/sec (c) 14 m/sec (d) 0.7 m/sec Ans .a (26)
(a) 15 : 14 (b) √15:√14 (c) 14 : 15 (d) √14:√15 Ans. d (6)
A thin uniform circular ring is rolling down an inclined plane of inclination 30° without slipping. Its linear acceleration along the inclined plane will be (a) g/2 (b) g/3 (c) g/4 (d) 2g/3 Ans. c (8)
(a) Ring, disc, sphere (b) Sphere, disc, ring (c) Disc, ring, sphere (d) Sphere, ring, disc Ans. b (16)
(a) 5/7 g sin θ (b) 3/5 g sin θ (c) 2/7 g sin θ (d) 2/5 g sin θ Ans. a (6)
(a) √(3/4) gh (b) √(4/3)gh (c) √4gh (d) √2gh Ans. b (19)
A body of moment of inertia of 3 kg-m2 rotating with an angular velocity of 2 rad/sec has the same kinetic energy as a mass of 12 kg moving with a velocity of (a) 8 m/s (b) 0.5 m/s (c) …
(a) 350 N-m (b) 440 N-m (c) 531 N-m (d) 628 N-m Ans. c (14)
(a) 10 J (b) 100 J (c) 500 J (d) 250 J Ans. d (25)
(a) 0.12 J–s (b) 12 J–s (c) 1.2 J-s (d) 1.12 J-s Ans. a (10)
(a) 0.3 rad/s (b) 5.3 rad/s (c) 10.3 rad/s (d) 89.3 rad/s Ans. c (9)
(a) 0.3 rad/s (b) 5.3 rad/s (c) 10.3 rad/s (d) 89.3 rad/s Ans. c (5)
Moment of inertia of uniform rod of mass M and length L about an axis through its centre and perpendicular to its length is given by ML2/12 . Now consider one such rod pivoted at its centre, free to rotate …
A smooth uniform rod of length L and mass M has two identical beads of negligible size, each of mass m, which can slide freely along the rod. Initially the two beads are at the centre of the rod and …
Two discs of moment of inertia I1 and I2 and angular speeds ω1 and ω2 are rotating along collinear axes passing through their centre of mass and perpendicular to their plane. If the two are made to rotate together along the …
The position of a particle is given by : →r = (^i+2^j-^k) and momentum →p =(3^i+4^j-2^k) . The angular momentum is perpendicular to (a) X-axis (b) Y-axis (c) Z-axis (d) Line at equal angles to all the three axes Ans. …
A circular platform is free to rotate in a horizontal plane about a vertical axis passing through its center. A tortoise is sitting at the edge of the platform. Now, the platform is given an angular velocity w0. When the …
(a) Mω (b) (M+4m)ω/M (c) (M-4m)ω/M+4m (d) Mω/4m Ans. a (8)
(a) 1/4 RQ (b) 3/8 RQ (c) 3/5 RQ (d) 2/5 RQ Ans. c (81)
(2^i-4^j+2^k)N acts at a point metre(3^i +2^j-4^k) from the origin. The magnitude of torque is (a) Zero (b) 24.4 N-m (c) 0.244 N-m (d) 2.444 N-m Ans. b (7)
Two circular discs A and B are of equal masses and thickness but made of metals with densities dA and dB (dA>dB) . If their moments of inertia about an axis passing through centres and normal to the circular faces …
The moment of inertia of a solid sphere of density ρ and radius R about its diameter is (a) (105/176)R5ρ (b) (105/176)R2ρ (c) (176/105)R5ρ (d) (176/105)R2ρ Ans. c (10)
A flywheel of moment of inertia 0.32 kg–m2 is rotated steadily 120 rad/s at by a 50 w electric motor. The kinetic energy of the flywheel is (a) 4608 J (b) 1152 J (c) 2304J (d) 6912J Ans. …
The angular velocity of a body is →w= 2^j+3^k+4^k and a torque →τ = ^j+2^k+3^k acts on it. The rotational power will be (a) 20 W (b) 15 W (c) √17 W (d) √17 W Ans. a (8)
(a) Disc (b) Ring (c) Solid sphere (d) All will make same number of rotations Ans. d (15)
(a) 400% (b) 800% (c) 200% (d) 100% Ans. b (13)
A wheel is rotating with an angular speed of 20 rad/s . It is stopped to rest by applying a constant torque in 4s . If the moment of inertia of the wheel about its axis is 0.20 kg-m2, then …
(a) √4 : √3 (b)√3: √4 (c) √3:√2 (d) √2:√3 Ans. a (4)
c HCl molecule about an axis passing through its centre of mass and perpendicular to the line joining the H+ and Cl– ions will be, if the interatomic distance is 1 Å (a) 0.641 x 10-47 kg.m2 (b) 1.61 x …
Three rings each of mass M and radius R are arranged as shown in the figure. The moment of inertia of the system about YY’ will be (a) 3 MR2 (b) 3/2 MR2 (c) 5 MR2 (d) 7/2 MR2 Ans. d …
Four thin rods of same mass M and same length l, form a square as shown in figure. Moment of inertia of this system about an axis through centre O and perpendicular to its plane is (a) 4/3 Ml2 (b) …
A circular disc X of radius R is made from an iron plate of thickness t, and another disc Y of radius 4R is made from an iron plate of thickness t/4 . Then the relation between the moment of …
The string of a simple pendulum is replaced by a uniform rod of length L and mass M. If the mass of the bob of the pendulum is m, then for small oscillations its time period would be (assume radius …
A ball of radius 11 cm and mass 8 kg rolls from rest down a ramp of length 2m. The ramp is inclined at 35° to the horizontal. When the ball reaches the bottom, its velocity is (sin 35o = …
A ring takes time t1 in slipping down an inclined plane of length L and takes time t2 in rolling down the same plane. The ratio t1/t2 is (a) √2:1 (b) 1:√2 (c) 1 : 2 (d) 2 : 1 Ans. …
A hollow cylinder is rolling on an inclined plane, inclined at an angle of 30° to the horizontal. Its speed after travelling a distance of 10 m will be (a) 49 m/sec (b) 0.7 m/sec (c) 7 m/sec (d) Zero …