MAH-MHT CET (PCM/PCB) entrance exam Question Bank Solutions

An `alpha` - particle of energy 5 MeV is scattered through 180° by gold nucleus. The distance of closest approach is of the order of ______.

A molecule of water on the surface experiences a net ______.

A 220 V input is supplied to a transformer. The output circuit draws a current of 2.0 A at 440 V. If the ratio of output to input power is 0.8, then the current drawn by primary winding is ______.

Two masses M₁ and M₂ are accelerated uniformly on frictionless surface as shown in the figure. The ratio of the tensions `"T"_1/"T"_2` is ______.

'Half-life' of a radioactive substance accounts for ______.

Smaller drops of a liquid are generally more spherical than larger drops, because ____________.

In a sphere of influence, the liquid molecule at its centre is ______.

If bullet of mass 'm₁' is fired from a gun of mass 'm₂' with a speed of 'V₁', then the recoil velocity of gun is ______.

A uniform current is flowing along the length of an infinite, straight, thin, hollow cylinder of radius 'R'. The magnetic field 'B' produced at a perpendicular distance 'd' from the axis of the cylinder is plotted in a graph. Which of the following figures looks like the plot?

Assertion: A transfonner cannot work on D.C. supply.

Reason: D.C. changes neither in magnitude nor in direction.

The half-life of a radioactive sample undergoing `alpha` - decay is 1.4 x 10¹⁷ s. If the number of nuclei in the sample is 2.0 x 10²¹, the activity of the sample is nearly ____________.

A transformer having efficiency of 80% is working on 200 V and 6 kW power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil respectively are ____________.

A conductor in the fom1 of a right angle `\triangle` ABC with AB = 3 cm and BC = 4 cm carries a current of 15 A. There is a uniform magnetic field of 8 T perpendicular to the plane of the conductor. The force on the conductor will be ______.

A body of mass 'M' moving with velocity 'V' explodes into two equal parts. If one part comes to rest and the other part moves with velocity 'v₀'. What would be the value of 'v₀'?

The motion of a rocket in upward direction with high speed is based on the principle of conservation of ______.

After 1 hour, `(1/8)^"th"` of the initial mass of a certain radioactive isotope remains undecayed. The half-life of the isotopes is ______.

A 100% efficient transformer has 100 turns in the primary and 50 turns in its secondary coil. If the current in the secondary coil is 6 A, then the current in the primary coil is ______.

Two radioactive materials Y₁ and Y₂ have decay constants '5`lambda`' and `lambda` respectively. Initially they have same number of nuclei. After time 't', the ratio of number of nuclei of Y₁ to that of Y₂ is `1/"e"`, then 't' is equal to ______.

What percentage of radioactive substance is left after five half-lives?

What is the half-life period of a radioactive material if its activity drops to 1/16^th of its initial value of 30 years?