HSC Science (Computer Science) १२ वीं कक्षा - Maharashtra State Board Important Questions

Why a detergent powder is mixed with water to wash clothes?

Define the surface energy of the liquid.

Obtain an expression for total kinetic energy of a rolling body in the form

`1/2 (MV^2)[1+K^2/R^2]`

For polyatomic molecules having 'f' vibrational modes, the ratio of two specific heats,Cp/Cv  is..........

A body of moment of inertia 5 kgm² rotating with an angular velocity 6 rad/s has the same kinetic energy as a mass of 20 kg moving with a velocity of ......

The kinetic energy of a rotating body depends upon................

1. distribution of mass only.
2. angular speed only.
3. distribution of mass and angular speed.
4. angular acceleration only.

State the theorem of perpendicular axes about moment of inertia.

State an expression for the moment of intertia of a solid uniform disc, rotating about an axis passing through its centre, perpendicular to its plane. Hence derive an expression for the moment of inertia and radius of gyration:

i. about a tangent in the plane of the disc, and

ii. about a tangent perpendicular to the plane of the disc.

A thin wire of length L and uniform linear mass density r is bent into a circular coil. M. I. of the coil about tangential axis in its plane is ................................

1. `(3rhoL^2)/(8pi^2)`
2. `(8pi^2)/(3rhoL^2)`
3. `(3rhoL^3)/(8pi^2)`
4. `(8pi^2)/(3rhoL^3)`

A body starts rotating from rest. Due to a couple of 20 Nm it completes 60 revolutions in one minute. Find the moment of inertia of the body.

The moment of inertia of a thin uniform rod of mass M and length L, about an axis passing through a point, midway between the centre and one end, perpendicular to its length is .....

(a)`48/7ML^2`

(b)`7/48ML^2`

(c)`1/48ML^2`

(d)`1/16ML^2`

A wheel of moment of inertia 1 Kgm² is rotating at a speed of 40 rad/s. Due to friction on the axis, the wheel comes to rest in 10 minutes. Calculate the angular momentum of the wheel, two minutes before it comes to rest.

Derive an expression for kinetic energy, when a rigid body is rolling on a horizontal surface without slipping. Hence find kinetic energy for a solid sphere.

A solid cylinder of uniform density of radius 2 cm has mass of 50 g. If its length is 12 cm, calculate its moment of inertia about an axis passing through its centre and perpendicular to its length.

Choose the correct option.

If the pressure of an ideal gas decreases by 10% isothermally, then its volume will ______.

A solid sphere of mass 1 kg rolls on a table with linear speed 2 m/s, find its total kinetic energy.

A uniform solid sphere has radius 0.2 m and density 8 x 10³ kg/m³. Find the moment of
inertia about the tangent to its surface. (π = 3.142)

If a rigid body of radius ‘R’ starts from rest and rolls down an inclined plane of inclination
‘θ’ then linear acceleration of body rolling down the plane is _______.

The body is rotating with uniform angular velocity (w) having rotational kinetic energy (E). Its angular momentum (L) is: ...............

a) `(2E)/ω`

b) `E^2/ω`

c) `E/ω^2`

d) `E/(2ω)`

A uniform solid sphere has a radius 0.1 m and density 6 x 103 kg/m3• Find its moment of inertia about a tangent to its surface.