Physics Test 10...

A small block of mass m is pushed towards a movable wedge of mass 2m and height h with initial velocity u. All surfaces are smooth. The minimum value of u for which the block will reach the top of the wedge, is :-

A particle is released on a vertical smooth semi circular track from point X so that OX makes angle θ from the vertical (see figure). The normal reaction of the track on the particle vanishes at point Y where OY makes angle ϕ with the horizontal. Then :

An aeroplane flies along a  straight path  A to B and returns back again. The distance between  A & B is λ  and  the aeroplane maintains the constant speed  v with respect to air.  There is a steady wind with  a  speed u along line  AB. The total time taken by the aeroplane in the trip is :

The x-t graph of a particle undergoing simple harmonic motion is shown below. The acceleration of the particle at t = 4/3 s is

Steel ruptures when a shear of 3.5 × 10⁸ Nm^–2 is applied. The force needed to punch a 1 cm diameter hole in a steel sheet 0.3 cm thick is nearly :-

A square of side a is cut from a square of side '2a' as shown mass of this square with hole is M. Then its moment of inertia with respect to an axis passing through centre of mass and perpendicular to its plane will be :-

A pendulum clock keeps correct time at 0°C. The thermal coefficient of linear expansion of the material of the pendulum is α. If the temperature rises to t°C, then the clock loses per day by (in second) :-

A mixture of 2 moles of helium gas

(atomic mass = 4 amu) and 1 mole of argon gas (atomic mass = 40 amu) is kept at 300 K in a container. The ratio of the rms speeds  is :-

Two non-reactive monoatomic ideal gases have their atomic masses in the ratio 2 : 3. The ratio of their partial pressures, when enclosed in a vessel kept at a constant temperature, is 4 : 3. The ratio of their densities is :-

With what potential an electron should be accelerated so that its de Broglie wave-length becomes equal to the wave length of second line of Balmer series for He⁺ ion ?