MEDIUM
11th West Bengal Board
IMPORTANT
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A simple pendulum has time-period T1. The point of suspension is now moved upward according to the relation y=kt2k=1ms2 where y is the vertical displacement. The time period now becomes T2. The ratio of T12T22 is (g=10 ms2)

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Important Questions on Oscillations

MEDIUM
11th West Bengal Board
IMPORTANT

Two masses m1 and m2 are suspended together by a massless spring of constant k. When the masses are in equilibrium, m1 is removed without disturbing the system. The amplitude of oscillation is

EASY
11th West Bengal Board
IMPORTANT
The amplitude of a damped oscillator becomes 13rd in 2 s. If its amplitude after 6 s is 1n times the original amplitude, the value of n is
HARD
11th West Bengal Board
IMPORTANT

A uniform rod of length L and mass M is pivoted at the centre. Its two ends are attached to two springs of equal spring constants k. The springs are fixed to the rigid supports as shown in Fig 22.70, and rod is free to oscillate in the horizontal plane. The rod is gently pushed through a small angle θ in one direction and released. The frequency of oscillation is

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MEDIUM
11th West Bengal Board
IMPORTANT

The mass M shown in Fig 22.71 oscillates in simple harmonic motion with amplitude A. The amplitude of the point P is

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MEDIUM
11th West Bengal Board
IMPORTANT
A point mass is subjected to two simultaneous sinusoidal displacements in X-direction x1(t)=Asin ωt and x2(t)=Asin (ω t+2π3). Adding a third sinusoidal displacement x3(t)=B sin (ω t+ϕ) brings the mass to a complete rest. The values of B and ϕ are:
HARD
11th West Bengal Board
IMPORTANT

A small block is connected to one end of a massless spring of unstretched length 4.9 m. The other end of the spring is fixed. The system lies on a horizontal frictionless surface. The block is stretched by 0.2 m and released from rest at t=0. It then executes simple harmonic motion with angular frequency ω=π3 rad s-1. Simultaneously at t=0, a small pebble is projected with speed v from point P at an angle of 45° as shown in the figure. Point P is at a distance of 10 m from O. If the pebble hits the block at t=1 s, the value of v is g=10 m s-2

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MEDIUM
11th West Bengal Board
IMPORTANT

The amplitude of a damped oscillator decreases to 0.9 times its original magnitude is 5 s. In another 10 s it will decrease to α times its original magnitude, where α equals

HARD
11th West Bengal Board
IMPORTANT

An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M. The piston and the cylinder have equal cross-sectional area A. When the piston is in equilibrium, the volume of the gas is V0 and its pressure is p0. The piston is slightly displaced from the equilibrium position and released. Assuming that the system is completely isolated from its surroundings, the piston executes a simple harmonic motion with the frequency