Physics Spl

When two waves of the same amplitude, frequency and speed travel in opposite directions and collide with each other, then a standing wave is formed. It is usually seen in the bounded medium, like a string fixed at both ends. It is different from the travelling waves and does not appear to move along the medium. At fixed locations, it forms specific points called nodes (with zero displacement) and antinodes (with maximum displacement). It is an important concept in understanding musical instruments, resonance and wave behaviour in closed and open pipes. The standing waves help in visualizing how energy can be stored in waveforms.

Mechanical waves are of two types - transverse waves and longitudinal waves. It requires a medium to travel. The medium particles vibrate perpendicular to the direction of wave propagation in the case of transverse waves.  However, the particles oscillate parallel to the wave direction in the longitudinal waves as seen in sound waves. The sound waves propagate by exerting forces by the neighbouring particles. While the wave particles stay close to the original position, the energy is passed on through the interactions among the adjacent particles.

A disturbance that travels through the space or medium transferring energy without the net movement of particles is called a wave. Rather than moving along with the wave, the particles of the medium only oscillate about their mean position in a wave motion. The wave is fundamentally different as compared to the particle motion where the particles travel from one place to another. In a sound wave, the air molecules do not travel to the sound, they vibrate back and forth. The concept of wave motion is one of the most important concepts in knowing how energy is transmitted in various forms including light, sound and water waves.

I think 3 months for well preparations and ½ month i.e 15 days for complete revision and 1 month for mock papers and analysis are required to cover IISER Physics syllabus.

The main difference between the real and ideal gases is with respect to the kinetic theory. The ideal gas follows assumptions of the kinetic theory but the real gases do not follow it, especially when the temperature is low and there is high pressure.

The following points are applicable in the case of real gases:

• Real gas molecules do have finite volume.
• In such cases, intermolecular forces such as Van there Waals forces become significant.

According to the NCERT Solutions for Class 11 Physics Chapter 12 Kinetic Theory, the pressure is exerted due to gas molecules' collisions with the walls of the container. Each gas molecule has a certain mass and velocity. According to Newton's law, when the molecules collide with a wall, it changes momentum and this change in momentum exerts a force on the container wall. By considering the collisions from all molecules over a period in a unit area, the average force per unit area is called pressure. Mathematically, pressure P is:

p is the gas density.

In a sample, Root mean square (RMS) speed refers to the average of the squares of the speeds of all gas molecules. It helps in measuring the gas particles' speed and takes into account the kinetic energy. Mathematically, it is expressed as:

Here, T is the temperature in Kelvin, k is the Boltzmann constant, and m is the mass of one molecule. M is the molar mass and R is the universal gas constant. The RMS speed is calculated by kinetic theory using the relationship between molecular motion, kinetic energy and pressure. RMS speed shows with which speed the molecules are moving in a gas sample and increases with temperature.