Physics Test 23...

A long horizontal rod has a bead which can slide along its length. The bead is initially placed at a distance L from one end A of the rod. The rod is set in angular motion about A with constant angular acceleration α. If the coefficient of friction between the rod and the bead is μ, and gravity is neglected, then the time after which the bead starts slipping is

The number of α and β^- particle emitted during the radioactive decay chain starting from 

A particle P is projected with velocity u₁ at an angle of 30° with the horizontal. At the same instant, another particle Q is thrown vertically upwards with velocity u₂ from a point vertically below the highest point of the path of P. The necessary condition for the two particles to collide at the highest point is

An open cubical tank completely filled with water is kept on a horizontal surface. Its acceleration is then slowly increased to 2 m/s² as shown in the figure. The side of the tank is 1 m. The mass of water that would spill out of the tank will be

A small ball rolls off the top landing of a staircase. It strikes the midpoint of the first step and then the midpoint of the second step. The steps are smooth, and identical in height and width. The coefficient of restitution between the ball and the first step is

A spherical black body with a radius of 12 cm radiates 450 W power at 500 K. If the radius were halved and the temperature doubled, the power radiated in watts would be

An LCR series circuit with 100 Ω  resistance is connected to an ac source of 200 V and angular frequency 300 rad/s. When only the capacitance is removed, the current lags behind the voltage by 60º. When only the inductance is removed, the current leads the voltage by 60º. The current in the LCR circuit is

A flywheel rotates about an axis. Due to friction at the axis, it experiences an angular retardation proportional to its angular velocity. If its angular velocity falls to half while it makes n rotations, how many more rotations will it make before coming to rest?

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its absolute temperature. The ratio  for the gas is

In a parallel plate capacitor of capacitance C, a metal sheet is inserted between the plates, parallel to them. The thickness of the sheet is half of the separation between the plates. The capacitance now becomes