HSC Science Class 11 - Tamil Nadu Board of Secondary Education Question Bank Solutions

Explain how Newton arrived at his law of gravitation from Kepler’s third law.

A flywheel rotates with uniform angular acceleration. If its angular velocity increases from `20pi` rad/s to `40pi` rad/s in 10 seconds. Find the number of rotations in that period.

Explain how geocentric theory is replaced by heliocentric theory using the idea of retrograde motion of planets.

Explain in detail the Eratosthenes method of finding the radius of Earth.

Describe the measurement of Earth’s shadow (umbra) radius during the total lunar eclipse

The following photographs are taken from the recent lunar eclipse which occurred on January 31, 2018. Is it possible to prove that Earth is a sphere from these photographs?

A student was asked a question ‘why are there summer and winter for us? He replied as ‘since Earth is orbiting in an elliptical orbit, when the Earth is very far away from the Sun (aphelion) there will be winter, when the Earth is nearer to the Sun (perihelion) there will be winter’. Is this answer correct? If not, what is the correct explanation for the occurrence of summer and winter?

The Moon I_o orbits Jupiter once in 1.769 days. The orbital radius of the Moon I_o is 421700 km. Calculate the mass of Jupiter?

A certain number of spherical drops of a liquid of radius R coalesce to form a single drop of radius R and volume V. If T is the surface tension of the liquid, then

The wettability of a surface by a liquid depends primarily on

Explain elasticity using intermolecular forces.

Define the surface tension of a liquid.

Mention the S.I unit and dimension of surface tension.

How is surface tension related to surface energy?

Define the angle of contact for a given pair of solid and liquid.

Distinguish between cohesive and adhesive forces.

What are the factors affecting the surface tension of a liquid?

What do you mean by capillarity or capillary action?

A drop of oil placed on the surface of water spreads out. But a drop of water place on oil contracts to a spherical shape. Why?

Obtain an expression for the excess of pressure inside a

1. liquid drop
2. liquid bubble
3. air bubble