Everyday Science

Heat from the fire reaches the person primarily through radiation, which is the transfer of heat via electromagnetic waves. Conduction requires direct contact, convection involves fluid movement, and reflection is the bouncing of heat, not its transfer to a person.

Cobalt is a ferromagnetic material, along with iron and nickel. Ferromagnetic materials are strongly attracted by magnets and can themselves be permanently magnetized. Cobalt's magnetic attraction is strong, not weak, and it is one of the few metals that exhibit ferromagnetism at room temperature. Therefore, the correct description is that cobalt is strongly attracted by a magnet, making option A correct.

Bats use ultrasonic waves to navigate and find prey in the dark through echolocation, which involves emitting high-frequency sound waves and interpreting their echoes.

Blotting paper absorbs ink primarily through capillary action, where the narrow spaces in the paper draw the liquid ink upward by adhesion and cohesion forces. This phenomenon allows the ink to be absorbed quickly and efficiently.

A person's unique voice is recognized by its quality (timbre), which is determined by the complex combination of frequencies and harmonics, not just pitch. Hence, 'Quality' is the correct answer.

Coating iron pipes with a layer of zinc to prevent corrosion is called galvanization. Zinc acts as a protective barrier and prevents rusting of iron.

Water is a highly effective coolant because it has a very high specific heat capacity, meaning it can absorb a lot of heat before its temperature rises significantly, making it ideal for cooling car engines.

The cracking sound heard when dry hair is combed with a hard rubber comb is caused by small electric sparks. This occurs because the comb and hair become charged by friction (triboelectric effect), leading to a rapid discharge of static electricity. The sudden discharge produces tiny sparks, which create the characteristic crackling sound. It is not simply the hair 'barging' against the comb or just the rubbing action, but the static electricity discharge that causes the sound.

Ibn Sina, also known as Avicenna, wrote the famous medical encyclopedia 'Al-Qanun fi al-Tibb' (The Canon of Medicine), which extensively discusses human physiology and medicine. This work was a standard medical text for centuries.

Gypsum is a non-metallic mineral commonly used in construction and agriculture, whereas manganese, magnesium, and bauxite are metallic minerals or ores containing metals.