Explanation

Transistors primarily act as current amplifiers in a circuit.

They can increase the current flowing through a circuit, which can also be used for voltage amplification and switching.

Explanation

 In an isothermal process, the temperature remains constant, so the internal energy of an ideal gas also remains constant.

Explanation

Reactivity in organic compounds is largely determined by the presence of multiple bonds.

Ethyne has a triple bond, which is the most reactive bond due to the greater electron density and availability for participation in reactions.

Explanation

The reactivity of aldehydes towards nucleophilic addition depends on the size of the alkyl group attached to the carbonyl carbon.

Formaldehyde (HCHO) has no alkyl groups attached to the carbonyl carbon, making it the most reactive

Because there is no steric hindrance, and the electron-donating effect is minimal.

Explanation

Among the listed liquids, heptane (C₇H₁₄) has the greatest molecular weight

Thus the strongest intermolecular forces, lead to the lowest vapor pressure at the same temperature

Explanation

Ammonia (NH₃) has a higher boiling point than phosphine (PH₃)

Ammonia exhibits hydrogen bonding, a stronger intermolecular force than the dipole-dipole forces in phosphine.

Explanation

Be(OH)₂ is an amphoteric hydroxide, meaning it can act as both an acid and a base.

Mg(OH)₂ and Ca(OH)₂ are basic hydroxides.

Explanation

A liquid crystal is a state of matter that exhibits properties of both liquids and crystals.

It requires the molecules to have a specific structure, often long and rigid, to form ordered phases.

While soap can form structures similar to liquid crystals when mixed with water (forming micelles), pure soap is not a liquid crystal.

The other options listed, DNA, cholesteryl format, and engine oil, can all exhibit liquid crystal properties under certain conditions. 

Explanation

Beta particles are high-energy electrons or positrons that interact frequently with air molecules.

These collisions cause them to change direction randomly, resulting in a zigzag or erratic path. 

Explanation

When a gas expands suddenly (an adiabatic expansion), it does work on the surroundings without any heat exchange.

As a result, the internal energy of the gas decreases, leading to a decrease in temperature.