Explanation

According to the law of reflection, angle of incidence = angle of reflection.

So, if light strikes at 30°, it reflects at 30°.

Explanation

Bronchial respiration refers to respiration through gills, mainly seen in fishes.

Gills extract dissolved oxygen from water and expel carbon dioxide.

Explanation

The charges of Proton, Electron, Neutron respectively are:

• Proton: Positive charge (+1)
• Electron: Negative charge (-1)
• Neutron: Neutral charge (0)

Explanation

Amateur means کوئی ایسا شخص جو پیشہ ورانہ مہارت یا تربیت کے بغیر کچھ کرتا ہے

Non-professional means کوئی ایسا شخص جو پیشہ ورانہ مہارت یا تربیت کے بغیر کچھ کرتا ہے

Explanation

Light : Darkness → opposites means روشنی : اندھیرے

Sanity : Madness → opposites means سنجیدگی : جنون

Explanation

At 170°C, ethanol undergoes acid-catalyzed dehydration to form ethene (C₂H₄).

Concentrated H₂SO₄ acts as a dehydrating agent, removing water from ethanol.

Explanation

Maltose is made of two glucose molecules, so both structural units are the same.

Lactose = glucose + galactose (different units).

Sucrose = glucose + fructose (different units).

Explanation

Absorbance (A) is a logarithmic ratio of incident to transmitted light; hence, it is unitless.

In the Beer-Lambert law:

A=ε⋅C⋅L, only ε (molar absorptivity) carries units to balance the equation.

Explanation

Secondary syphilis commonly presents with fever, skin rashes (especially on palms and soles), and joint pain.

It occurs weeks after the primary sore and indicates systemic spread of the infection.

Explanation

A virus consists of a protein coat (capsid) that surrounds its genetic material (DNA or RNA).

It lacks cellular structures.

It is not considered a complete cell.