Waves — Physics STD 11 Science — Question

What is the ratio of r.m.s. speed of oxygen and hydrogen molecules at the same temperature?

Answer the following :
The triple-point of water is a standard fixed point in modern thermometry. Why? What is wrong in taking the melting point of ice and the boiling point of water as standard fixed points (as was originally done in the Celsius scale)?

Fill in the blanks by suitable conversion of units:
G = 6.67 × 10^-11 N m² (kg)^-2 = .... (cm)³ s^-2 g^-1

Explain why a violin note and sitar note may have the same frequency, yet we can distinguish between the two notes.

A metal block of density 6000kg m^-3 and mass 1.2kg is suspended through a spring of spring constant 200N m^-1. The spring-block system is dipped in water kept in a vessel. The water has a mass of 260g and the block is at a height 40cm above the bottom of the vessel. If the support to the spring is broken, what will be the rise in the temperature of the water. Specific heat capacity of the block is 250Jkg^-1 K^-1 and that of water is 4200Jkg^-1 K^-1. Heat capacities of the vessel and the spring are negligible.

If two row-boats happen to sail parallel, and close of each other, they experience a force which pulls them towards each other. Give reasons for it.

Fill in the blanks using the word(s) from the list appended with statement:
Surface tension of liquids generally . . . with temperatures. (increases/ decreases)

Why does a diamond shine more than a glass piece cut to the same shape?

What velocity will you give to a donkey and what velocity to a monkey so that both escape the gravitational field of the earth?

Should the speed of two artificial satellites of the earth having different masses but the same orbital radius, be the same?