Science (English Medium) इयत्ता ११ - CBSE Question Bank Solutions

The displacement of a particle is represented by the equation `y = 3 cos (pi/4 - 2ωt)`. The motion of the particle is ______.

The displacement of a particle is represented by the equation y = sin³ωt. The motion is ______.

The displacement of a particle varies with time according to the relation y = a sin ωt + b cos ωt.

Motion of a ball bearing inside a smooth curved bowl, when released from a point slightly above the lower point is ______.

1. simple harmonic motion.
2. non-periodic motion.
3. periodic motion.
4. periodic but not S.H.M.

Displacement vs. time curve for a particle executing S.H.M. is shown in figure. Choose the correct statements.

1. Phase of the oscillator is same at t = 0 s and t = 2s.
2. Phase of the oscillator is same at t = 2 s and t = 6s.
3. Phase of the oscillator is same at t = 1 s and t = 7s.
4. Phase of the oscillator is same at t = 1 s and t = 5s.

What is the ratio of maxmimum acceleration to the maximum velocity of a simple harmonic oscillator?

The earth has a radius of 6400 km. The inner core of 1000 km radius is solid. Outside it, there is a region from 1000 km to a radius of 3500 km which is in molten state. Then again from 3500 km to 6400 km the earth is solid. Only longitudinal (P) waves can travel inside a liquid. Assume that the P wave has a speed of 8 km s^–1 in solid parts and of 5 km s^–1 in liquid parts of the earth. An earthquake occurs at some place close to the surface of the earth. Calculate the time after which it will be recorded in a seismometer at a diametrically opposite point on the earth if wave travels along diameter?

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the amplitude.

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the wavelength.

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the frequency.

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the wave velocity.

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the particle velocity amplitude.. 

Given a + b + c + d = 0, state whether the following statement is correct or incorrect:

b + c must lie in the plane of a and d if a and d are not collinear, and in the line of a and d, if they are collinear.

Establish the following vector inequalities geometrically or otherwise:

1. | a+b | ≤ |a| + |b|
2. |a + b| ≥ | |a| - |b| |
3. |a - b| ≤ |a| + |b|
4. |a-b| ≥ | |a| - |b| |

When does the equality sign above apply?

Two heavy spheres each of mass 100 kg and radius 0.10 m are placed 1.0 m apart on a horizontal table. What is the gravitational force and potential at the mid point of the line joining the centers of the spheres? Is an object placed at that point in equilibrium? If so, is the equilibrium stable or unstable?

A star 2.5 times the mass of the sun and collapsed to a size of 12 km rotates with a speed of 1.2 rev. per second. (Extremely compact stars of this kind are known as neutron stars. Certain stellar objects called pulsars belong to this category). Will an object placed on its equator remain stuck to its surface due to gravity? (mass of the sun = 2 x 10³⁰ kg).

Give the magnitude and direction of the net force acting on a drop of rain falling down with a constant speed.

The driver of a three-wheeler moving with a speed of 36 km/h sees a child standing in the middle of the road and brings his vehicle to rest in 4.0 s just in time to save the child. What is the average retarding force on the vehicle? The mass of the three-wheeler is 400 kg and the mass of the driver is 65 kg.

If the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks?

Read each statement below carefully, and state, with reasons, if it is true or false;

 During rolling, the force of friction acts in the same direction as the direction of motion of the CM of the body