HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Physics

With the help of a neat labelled diagram, describe the Geiger- Marsden experiment

Thorium ₉₀Th²³² is disintegrated into lead ₈₂Pb²⁰⁰. Find the number of α and β particles emitted in disintegration.

A thin walled hollow cylinder is rolling down an incline, without slipping. At any instant, without slipping. At any instant, the ratio "Rotational K.E.: Translational K.E.: Total K.E." is ______.

Answer in brief:

Why are curved roads banked?

Do we need a banked road for a two-wheeler? Explain.

On what factors does the frequency of a conical pendulum depend? Is it independent of some factors?

While driving along an unbanked circular road, a two-wheeler rider has to lean with the vertical. Why is it so? With what angle the rider has to lean? Derive the relevant expression. Why such a leaning is not necessary for a four wheeler?

Somehow, an ant is stuck to the rim of a bicycle wheel of diameter 1 m. While the bicycle is on a central stand, the wheel is set into rotation and it attains the frequency of 2 rev/s in 10 seconds, with uniform angular acceleration. Calculate:

1. The number of revolutions completed by the ant in these 10 seconds.
2. Time is taken by it for first complete revolution and the last complete revolution.

The coefficient of static friction between a coin and a gramophone disc is 0.5. Radius of the disc is 8 cm. Initially the center of the coin is 2 cm away from the center of the disc. At what minimum frequency will it start slipping from there? By what factor will the answer change if the coin is almost at the rim? (use g = π²m/s²)

Answer in Brief:

A flywheel used to prepare earthenware pots is set into rotation at 100 rpm. It is in the form of a disc of mass 10 kg and a radius 0.4 m. A lump of clay (to be taken equivalent to a particle) of mass 1.6 kg falls on it and adheres to it at a certain distance x from the center. Calculate x if the wheel now rotates at 80 rpm.

Starting from rest, an object rolls down along an incline that rises by 3 in every 5 (along with it). The object gains a speed of `sqrt10` m/s as it travels a distance of `5/3` m along the incline. What can be the possible shape/s of the object? 

Multiple Choice Question.

Two capillary tubes of radii 0.3 cm and 0.6 cm are dipped in the same liquid. The ratio of heights through which the liquid will rise in the tubes is

Why is a low-density liquid used as a manometric liquid in a physics laboratory?

What is an incompressible fluid?

Obtain an expression for conservation of mass starting from the equation of continuity.

The speed of water is 2m/s through a pipe of internal diameter 10 cm. What should be the internal diameter of the nozzle of the pipe if the speed of the water at nozzle is 4 m/s?

With what velocity does water flow out of an orifice in a tank with gauge pressure 4 × 10⁵ N/m² before the flow starts? Density of water = 1000 kg/m³.

Choose the correct option:

Intensity of the magnetic field of the earth at the point inside a hollow iron box is ______.

Choose the correct option.

If the rms current in a 50 Hz AC circuit is 5A, the value of the current 1/300 seconds after its value becomes zero is ______.

Choose the correct option.

In a circuit L, C and R are connected in series with an alternating voltage of frequency f. the current leads the voltage by 45°. The value of C is ______.