Explanation

Flatworms (phylum Platyhelminthes) have unsegmented, flat bodies.

Earthworms and tapeworms have segmented bodies.

Explanation

The speed of sound in steel at 20°C is approximately 5100–5200 m/s, with 5130 m/s being a widely accepted value.

Sound travels faster in solids like steel due to their high density and elasticity compared to gases and liquids.

Explanation

• The female reproductive part of a flower is called the Pistil.

It consists of three parts:

1. Stigma (receives pollen grains)
2. Style (connects stigma to ovary)
3. Ovary (contains ovules/eggs)

The pistil is also sometimes referred to as the carpel, which is a modified leaf that forms the female reproductive organ.

Explanation

• The critical angle is the angle of incidence at which the angle of refraction is 90°, and beyond which total internal reflection occurs.
• This concept is crucial in understanding optical phenomena like fiber optics and prisms.

Explanation

Explanation

 A convex lens is thicker at the centre than at the edges. 

A camera uses a convex lens to focus light rays and form an image on a piece of film or a digital sensor at the back, capturing the scene in front of it.

Explanation

• The Moon is a non-luminous object because it does not produce its own light.
• Instead, it reflects the light of the Sun.

Explanation

Pyridine has a lone pair on nitrogen that is not involved in resonance, making it readily available for donation.

In aniline and phenol, lone pairs are delocalized into the aromatic ring, reducing basicity.

Explanation

Explanation

Open garbage dumps release toxic gases into the air, leading to air pollution (e.g., methane, ammonia).

When rainwater passes through waste, it forms leachate, which contaminates groundwater and causes water pollution.