CBSE
Multiple Choice QuestionsIn the figure, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t = 2 sec is
0.2 kg m sec-1
- 0.2 kg m sec-1
0.1 kg m sec-1
- 0.4 kg m sec-1
The direction of the angular velocity vector is along
the tangent to the circular path
the inward radius
the outward radius
the axis of rotation
A ladder is leaned against a smooth wall and it is allowed to slip on a frictionless floor. Which figure represents trace of its centre of mass.
In an orbital motion, the angular momentum vector is
along the radius vector
parallel to the linear momentum
in the orbital plane
perpendicular to the orbital plane
The pressure exerted by an electromagnetic wave of intensity I ( watt/m2 ) on a nonreflecting surface is [ c is the velocity of light ]
Ic
Ic2
I/c
I/c2
Assertion: A judo fighter in order to throw his opponent on to the mat tries to initially bend his opponent and then rotate him around his hip.
Reason: As the mass of the opponent is brought closer to the fighter's hip, the force required to throw the opponent is reduced.
If both assertion and reason are true and reason is the correct explanation of the assertion
If both assertion and reason are true but reason is not the correct explanation of the assertion
If assertion is true, but reason is false
Both assertion and reason are false statements
The moment of inertia of a rod about an axis through its centre and perpendicular to it is ML2 ( where M is the mass and L, the length of the rod). The rod is bent in the middle so that the two halves make an angle of 60°. The moment of inertia of the bent rod about the same axis would be
ML2
ML2
ML2
Assertion: : For a system of particles under central force field, the total angular momentum is conserved.
Reason: The torque acting on such a system is zero.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
A man of mass 60 kg records his wt on a weighing machine placed inside a lift. The ratio of wts. of man recorded when lift is ascending up with a uniform speed of 2 m/s to when it is descending down with a uniform speed of 4 m/s will be
0.5
1
2
none of these
The direction of the angular velocity vector is along
the tangent to the circular path
the inward radius
the outward radius
the axis of rotation
