Explanation

A solar eclipse occurs when the Moon comes between the Earth and the Sun.

Most commonly, we observe a partial eclipse, where only part of the Sun is obscured by the Moon.

Explanation

Most low Earth orbit space stations, like the ISS, complete one full orbit in about 90 minutes.

This allows them to circle the Earth roughly 16 times per day.

Explanation

Light signals, such as semaphore flags or lantern flashes, were commonly used by sailors to communicate over distances.

These signals conveyed messages visually before the invention of modern communication tools.

Explanation

A chemical change alters both the appearance and the composition of a substance.

Examples include rusting of iron or burning of wood, where new substances are formed.

Explanation

The galactic bulge is the bright, dense center of a spiral galaxy.

It contains old stars.

It often a supermassive black hole at the core.

Explanation

• When an object reflects all the component colors of light, it appears white.
• This is because the object is reflecting all the wavelengths of visible light, which are then perceived by our eyes as white.
• If an object absorbs all seven colors of light (i.e., all the wavelengths of visible light), it appears black.

Explanation

Undersea earthquakes displace a large volume of water, generating powerful sea waves.

This sudden movement creates a tsunami, which can travel across oceans at high speeds.

Explanation

Calculate the distance covered.

Distance = Speed × Time = 30 m/s × 10 s = 300 m.

Explanation

MRI (Magnetic Resonance Imaging) uses a strong magnetic field and radio waves to create detailed images of organs and tissues.

It does not use ionizing radiation, unlike X-rays or CT scans.

Explanation

Maxwell's equations led to the derivation of the speed of electromagnetic waves, including light.

The speed of light (c) is given by C = 1/√μ₀ε₀, where μ₀ is the permeability of free space and ε₀ is the permittivity of free space.