### NEET Physics - New - Oscillations and Waves

#### Question - 1

Spring of force constant k is cut into lengths of ratio 1 : 2 : 3. They are connected in series and the new force constant is k', Then they are connected in parallel and force constant is k". then k' : k" is:

• A 1:9
• B 1:11
• C 1:14
• D 1:6

#### Question - 2

A particle executes linear simple harmonic motion with an amplitude of 3 cm. When the particle is at 2 cm from the mean position, the magnitude of its velocity is equal to that of its acceleration. Then its time period in seconds is:

• A $\sqrt{5}$/2π
• B 4π/$\sqrt{5}$
• C 2π/$\sqrt{5}$
• D $\sqrt{5}$/π

#### Question - 3

A body of mass m is attached to the lower end of a spring whose upper end is fixed. The spring has negligible mass. When the mass m is slightly pulled down and released, it oscillates with a time period of 3 s. When the mass m is increased by 1 kg, the time period of oscillations becomes 5s. The value of m in kg is

• A 3/4
• B 4/3
• C 16/9
• D 9/16

#### Question - 4

When two displacements represented by yl = a sin (ωt) and y2 = b cos (ωt)are superimposed the motion is :

• A not a simple harmonic
• B simple harmonic with amplitude a/b
• C simple harmonic with amplitude $\sqrt { { a }^{ 2 }+{ b }^{ 2 } }$
• D simple harmonic with amplitude (a+b)/2

#### Question - 5

The oscillation of a body on a smooth horizontal surface is represented by the equation X = A cos (ωt), where X = displacement at time t, ω = frequency of oscillation. Which one of the following graph shows correctly variation of 'a' with 't?

• A
• B
• C
• D

#### Question - 6

If n1, n2 and n3 are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the string is given by:

• A $\frac{1}{n}=\frac{1}{n_1}+\frac{1}{n_2}+\frac{1}{n_3}$
• B $\frac{1}{\sqrt{n}}=\frac{1}{\sqrt{n_1}}+\frac{1}{\sqrt{n_2}}+\frac{1}{\sqrt{n_3}}$
• C $\sqrt{n}=\sqrt{n_1}+\sqrt{n_2}+\sqrt{n_3}$
• D $n=n_1+n_2+n_3$

#### Question - 7

The number of possible natural oscillations of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250 Hz are: (velocity of sound = 340m/s-1)

• A 4
• B 5
• C 7
• D 6

#### Question - 8

The equation of a simple harmonic wave is given by y = 3 sin π/2 (50t - x) where x and y are in meters and t is in seconds. The ratio of maximum particle velocity to the wave velocity is :

• A 3π/2
• B
• C 2π/3
• D

#### Question - 9

A simple pendulum performs simple harmonic motion about x = 0 with an amplitude a and time period T. The speed of the pendulum at x = a/2 will be:

• A πa/T
• B 3π2a/T
• C πa$\sqrt{3}$/T
• D πa$\sqrt{3/2}$/T

#### Question - 10

A particle is executing SHM along a straight line. Its velocities at.distances x1 and x2 from the mean position are V1 and V2, respectively. Its time period is:

• A $2\pi \sqrt { ({ x }_{ 1 }^{ 2 }+{ x }_{ 2 }^{ 2 })/({ V }_{ 1 }^{ 2 }+{ V }_{ 2 }^{ 2 }) }$
• B $2\pi \sqrt { ({ x }_{ 2 }^{ 2 }-{ x }_{ 1 }^{ 2 })/({ V }_{ 1 }^{ 2 }+{ V }_{ 2 }^{ 2 }) }$
• C $2\pi \sqrt { ({ x }_{ 2 }^{ 2 }-{ x }_{ 1 }^{ 2 })/({ V }_{ 1 }^{ 2 }-{ V }_{ 2 }^{ 2 }) }$
• D $2\pi \sqrt { ({ V }_{ 1 }^{ 2 }+{ V }_{ 2 }^{ 2 })/({ x }_{ 1 }^{ 2 }-x_{ 2 }^{ 2 }) }$