Explanation

 Lenz's law is a consequence of the law of conservation of energy. 

Lenz's law states that the induced current in a conductor always opposes the change in magnetic flux that caused it, which is essentially a way of ensuring that energy is conserved. 

Explanation

 The temperature coefficient of resistance indicates how the resistance of a material changes with temperature.

In semiconductors, as temperature increases, more charge carriers (electrons and holes) become available, so resistance decreases.

Therefore, the temperature coefficient is negative.

Explanation

In semiconductors, as the temperature increases, more electrons gain enough energy to jump from the valence band to the conduction band.

This increase in free charge carriers results in higher electrical conductivity.

This is opposite to metals, where conductivity decreases with temperature due to increased scattering of electrons.

Explanation

Ferromagnetic materials (such as iron, cobalt, and nickel) have a strong attraction to magnetic fields and can retain their magnetism even after the external magnetic field is removed.

This property makes them ideal for making permanent magnets.

• Diamagnetic materials are repelled by magnetic fields and cannot retain magnetism.

• Paramagnetic materials are weakly attracted to magnetic fields but do not retain magnetism after the external field is removed.

Explanation

Explanation

Diamond is a crystalline form of carbon where atoms are arranged in a regular, repeating lattice structure.

This structure gives diamond its hardness and brilliance, unlike coke or charcoal, which are amorphous.

Explanation

Diffusion is the movement of particles from high to low concentration and occurs rapidly in gases, slowly in liquids, but is negligible in solids.

In solids, particles are tightly packed and cannot move freely, so diffusion does not occur significantly.

Explanation

Explanation

When a book is stationary, the upward normal force from the table equals the downward gravitational force.

These balanced forces result in no motion, keeping the book at rest.

Explanation

A magnetic field exerts a force perpendicular to the motion of the charged particle, changing its direction but not its speed.

Since no work is done by the magnetic field, the kinetic energy stays constant.