A ball is released from certain height which losses 50% of its kinetic energy on striking the ground it will contain a height again

• $\frac{1}{4}\mathrm{th}$ of initial height

• $\frac{1}{2}\mathrm{th}$ of initial height

• $\frac{3}{4}$th of initial height

• None of the above

If applied torque on a system is zero, i.e.,Τ = 0 , then for that system

• ω = 0

• α = 0

• J = 0

• F = 0

A particle moves towards east for 2 s with velocity 15 m/s and move towards north for 8 s with velocity 5 m/s. Then, average velocity of the particle is

• 1 m/s

• 5 m/s

• 7 m/s

• 10 m/s

Match the following

• C- 2, D - 1

• A - 4, B - 3

• A - 3, C -2

• B-2, A - 1

If we increase kinetic energy of a body 300%, then per cent increase in its momentum is

• 50%

• 300%

• 100%

• 150%

Change in acceleration due to gravity is same upto a height h from each other the earth surface and below depth x then relation between x and his ( h and x<<<R_e )

• x = h

• x = 2h

• x = $\frac{\mathrm{h}}{2}$

• x = h²

Three points charges +q, -2q and +q are placed at points (x=0,  y=a,  z=0),  ( x=0,  y=0,  z=0 )  and  (x=a,  y=0,  z=0), respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are

• √2 qa along + y direction

• √2 qa along the line joining point

• qa along the line joining points (x = 0,y = 0, z = 0) and (x = a, y = a, z = 0)

• √2 qa along + x direction

A block B is pushed momentarily along a horizontal surface with an initial velocity v. If is the coefficient of vlicling friction between B and the surface, block B will come to rest after a time

• $\frac{\mathrm{v}}{\mathrm{g} \mathrm{\mu }}$

• $\frac{\mathrm{g} \mathrm{\mu }}{\mathrm{v}}$

• $\frac{\mathrm{g}}{\mathrm{v}}$

• $\frac{\mathrm{v}}{\mathrm{g}}$

A particle of mass M and charge Q moving with velocity v describes a circular path of radius R when subjected to a uniform transverse magnetic field of induction B. The work done by the field, when the particle completes one full circle, is

• $\left(\frac{\mathrm{M} {\mathrm{v}}^2}{\mathrm{R}}\right) 2\mathrm{\pi R}$

• zero

• $\mathrm{BQ} 2\mathrm{\pi R}$

• $\mathrm{BQv} 2\mathrm{\pi R}$

A particle of mass 100 g is thrown vertically upward with a speed of 5 m/s. The work done by the force of gravity during the time the particle goes up is 

• -0.5 J

• -1.25 J

• 1.25 J

• 0.5 J