Explanation

These six quantities (length, mass, electric current, time, intensity of light, and amount of substance) are the fundamental base quantities in the International System of Units (SI).

They are the basic building blocks of the SI system and are used to define all other quantities.

Explanation

According to the kinetic molecular theory, the pressure exerted by a gas is caused by the bombardment of gas molecules on the walls of the container.

The gas molecules are in constant motion, colliding with each other and the container walls, resulting in a force exerted on the walls.

This force is what we experience as pressure.

Explanation

The critical velocity (vc) is the minimum velocity an object must have to orbit the Earth without falling to the ground.

It is given by the formula:

vc = √(gR)

where:

• g is the acceleration due to gravity (approximately 9.8 m/s²)
• R is the radius of the Earth (approximately 6,371 kilometers)

Explanation

A Bunsen burner is made more stable by increasing its base area, which lowers its center of gravity and makes it less likely to tip over.

This is a common design principle in engineering, where a wider base provides greater stability.

Explanation

Latent heat of vaporization is the energy required to change a liquid into a gas (or vice versa) without changing its temperature.

Latent heat of fusion is the energy required to change a solid into a liquid (or vice versa) without changing its temperature.

Explanation

Steel is more elastic than rubber, glass, and wood.

Elasticity refers to the material's ability to return to its original shape after being deformed.

Steel has a higher modulus of elasticity (Young's modulus), meaning it can withstand greater stress and still return to its original shape.

Explanation

G is the gravitational constant, also known as the universal gravitational constant.

It is a fundamental constant of nature that describes the strength of gravitational attraction between objects.

The currently accepted numerical value of G is 6.673 × 10^-11 Nm^2 kg^-2.

Explanation

Efficiency is the ratio of output to input, often expressed as a percentage.

It represents how much of the input energy is actually converted into useful output energy, with the rest being lost as waste or heat.

Key Points:

• Energy is the ability to do work.
• Work is the transfer of energy through a force applied over a distance.
• Power is the rate at which work is done or energy is transferred.

Explanation

When a gas is heated in a container of fixed volume, the molecules of the gas:

• Move faster (their kinetic energy increases, causing them to move more rapidly)
• Collide more frequently with the container walls (resulting in increased pressure)
• Do not expand (the container volume is fixed)
• Do not move further apart (the density of the gas remains the same, as the volume

Explanation

Neutral equilibrium is a state where the body is balanced, but the slightest disturbance will not cause it to return to its original position or topple over.

In this state, the center of gravity (CG) remains at the same height, regardless of the slight tilt or displacement.

Key Points: 

• A body is in unstable equilibrium after slight tilt if its center of gravity remains above the point of contact.
  
• A body is in stable equilibrium after slight tilt if its center of gravity remains above the point of contact.