Explanation

Infrasonic sounds have frequencies below 20 Hz, which are too low for human hearing.

Ultrasonic refers to sounds above 20,000 Hz.

Audible is the range between 20 Hz and 20,000 Hz.

Explanation

The speed at a banked turn is given by:

v = √(rg tan(θ))

Given v = √(rg), we can equate:

√(rg tan(θ)) = √(rg)

This simplifies to:

tan(θ) = 1

θ = arctan(1) = 45°.

Explanation

When Thorium (Th) emits a beta particle (β⁻), a neutron converts into a proton, increasing atomic number by 1.

So Thorium (Z=90) becomes Protactinium (Z=91).

Explanation

• Venus and Mercury are the only planets in the solar system that do not have any natural satellites or moons.
• Likely due to their proximity to the Sun and gravitational influences.

Explanation

Refraction is the bending of light as it passes from one medium to another (e.g., air to water).

This occurs due to a change in the speed of light in different media.

Explanation

The K orbit, also known as the first electron shell.

• It can hold a maximum of 2 electrons.

The L orbit, also known as the second electron shell.

• It can hold a maximum of 8 electrons.

The M orbit, also known as the third electron shell.

• It can hold a maximum of 18 electrons.

Explanation

An alkali is a base that dissolves in water to give hydroxide (OH⁻) ions.

Common examples include sodium hydroxide (NaOH) and potassium hydroxide (KOH).

Explanation

A solution is a homogeneous mixture where one substance (solute) is completely dissolved in another (solvent).

Sea water: A true solution where salts (like NaCl) are completely dissolved in water.

Explanation

Two parallel conductors carrying current in the same direction attract each other due to magnetic fields they produce.

If currents flow in opposite directions, the force would be repulsive.

Explanation

In a suspension, the solute particles are large enough to be seen with the naked eye and are not completely dissolved in the solvent.

The solute particles can eventually settle at the bottom if left undisturbed.