Explanation

The radioactive decay equation shows a parent nucleus (91Pa^233) decaying into a daughter nucleus (92U^233) with the emission of a particle.

The parent nucleus has an atomic number of 91 (Protactinium), and the daughter nucleus has an atomic number of 92 (Uranium).

This increase in atomic number indicates that a beta particle (β) has been emitted.

Explanation

To determine the symbol of element B with five protons and six neutrons, we can follow these steps:

The number of protons (atomic number) determines the element. An element with five protons is boron (B).

The mass number (A) is the sum of protons and neutrons. For this element, it is 5 + 6 = 11.

Therefore, the symbol for this element is 11B.

Explanation

The atomic mass (also known as atomic weight) of an element is the total mass of protons and neutrons present in the nucleus of an atom.

This includes:

• Mass of protons (which defines the element)
• Mass of neutrons (which varies in different isotopes)

Explanation

• If the area of the parallel plate capacitor is doubled, the capacitance will also double.
• The capacitance of a parallel plate capacitor is directly proportional to the area of the plates: C = ε × (A/d)
  

Explanation

The direction of the electric force (F) and electric field intensity (E) are parallel to each other.

The electric field intensity is a vector quantity that points in the direction of the force that would be experienced by a test charge at a given point.

Explanation

Sound waves require a physical medium, such as air, water, or solid objects, to propagate.

They cannot travel through a vacuum because there are no particles to transmit the energy.

Explanation

In an optical fiber, the core is made of a material with a relatively high refractive index, typically glass or plastic with a high refractive index.

This allows the light to be confined and transmitted through the fiber via total internal reflection.

The cladding surrounding the core has a lower refractive index, which helps to keep the light within the core.

Explanation

If the direction of the magnetic field is reversed, the direction of the force exerted on a charged particle or a current-carrying wire will also be reversed.

This is because the force due to a magnetic field depends on the direction of the field.

The direction of the current or velocity, and the charge of the particle (if applicable).

Explanation

Metals are good conductors of electricity because they have free electrons, also known as conduction electrons or mobile electrons.

These electrons are not tightly bound to a specific atom and are free to move throughout the metal, carrying electrical current.

Explanation

The correct answer is: Light waves, Radio waves, Microwaves

This group consists only of electromagnetic waves, which are waves that propagate through the electromagnetic field.

They do not require a physical medium to propagate.