Explanation

Average velocity depends only on displacement and total time, not the path taken.

Hence, a body can follow straight, curved, or variable motion while having a calculable average velocity.

Explanation

Solar cells, also known as photovoltaic cells, convert solar energy (sunlight) directly into electrical energy.

They work by using semiconductor materials to absorb photons from sunlight and release electrons, generating electricity.

Explanation

Work is defined as force × displacement, so its unit is Newton × meter (Nm).

In SI units, 1 Nm = 1 joule (J), the standard unit of work.

Explanation

A central force always acts along the line joining the object and a fixed point (the center).

Gravitational and centripetal forces are specific examples of central force.

Explanation

The book is at rest with no net force or motion, so it is in static equilibrium.

Since any small push won’t topple it, it is also considered stable equilibrium on a flat surface.

Explanation

Convex mirrors diverge light rays, giving a wider field of view, helpful in traffic.

They form diminished, virtual, and upright images, making distant vehicles visible clearly.

Explanation

Mechanical waves require a medium (solid, liquid, or gas) to travel.

Examples include air (sound waves), ropes (vibrations), and water surface waves.

Explanation

A Geiger counter detects and measures ionizing radiation like alpha, beta, and gamma rays.

It is commonly used for radiation safety and monitoring.

Explanation

A semiconductor has electrical conductivity between a conductor and an insulator.

Its conductivity is small but can be controlled by temperature or doping.

Explanation

The chemical symbol C represents Carbon.

It is a non-metal element.

It is the basis of organic compounds and essential for all living organisms.