Two spheres of same size, one of mass 2 kg and another of mass 4 kg are dropped simultaneously from the top of Qutab Minar  ( height ≈ 72 m ). When they are 1 m  above the ground the two spheres have the same

• momentum

• kinetic energy

• potential energy

• acceleration

The moment of inertia of a rod about an axis through its centre and perpendicular to it is $\frac{1}{12}$ 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

• $\frac{1}{48}$ ML²

• $\frac{1}{12}$ML²

• $\frac{1}{24}$ ML²

• $\frac{{\mathrm{ML}}^2}{8\sqrt{3}}$

The voltage of clouds is 4 x 10 volt with respect to ground. In a lightening strike lasting 100 msec, a charge of 4 coulombs is delivered to the ground. The power of the lightning strike is

• 160 MW

• 80 MW

• 20 MW

• 500 MW

For inelastic collision between two spherical rigid bodies

• the total kinetic energy is conserved

• the total potential energy is conserved

• the linear momentum is not conserved

• the linear momentum is conserved

A person used force (F), shown in figure to move a load with constant velocity on surface. Identify the correct surface profile.

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

Assertion: A man in a closed cabin which is falling freely does not experience gravity.

Reason: Inertial and gravitational mass have equivalence.

• 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.

8.

A boat at anchor is rocked by waves whose crests are 100 m apart and velocity is 25 m/sec. The boat bounces up once  in  every

• 2500 s

• 75 s

• 4 s

• 0.25 s

By sucking through a straw, a student can reduce the pressure in his lungs to 750 mm of Hg ( densiy = 13.6 g/cm³). Using the straw, he can drink water from a glass upto a maximum depth of

• 10 cm

• 75 cm

• 13.6 cm

• 1.36 cm

A stone thrown into still water, creates a circular wave pattern moving radially outwards. Ifr is the distance measured from the centre of the pattern, the amplitude of the wave varies as

• r^1/2

• r^-1

• r²

• r^3/2