C++ | MCQs

Explanation

The presence of a dielectric material between the plates of a capacitor increases the capacitance of the capacitor.

The dielectric material reduces the electric field between the plates, allowing more charge to be stored on the plates, and thus increasing the capacitance.

Explanation

When two capacitors of equal capacitance (C) are connected in series, the equivalent capacitance (Ceq) is half the value of one capacitor:

Ceq = (C × C) / (C + C) = (C × C) / 2C = C/2

In this case, C = 8 µF, so:

Ceq = 8 µF / 2 = 4 µF

Therefore, the equivalent capacitance of the two 8 µF capacitors connected in series is 4 µF.

Explanation

When capacitors are connected in parallel, the total capacitance (Ct) increases, as the effective plate area and charge storage capacity increase.

The formula for total capacitance in parallel is: Ct = C1 + C2 + ... + Cn

In series connection, the total capacitance decreases, as the effective plate area and charge storage capacity decrease.

The formula for total capacitance in series is: 1/Ct = 1/C1 + 1/C2 + ... + 1/Cn

Explanation

The electrostatic force between two electrons is F Newton, and since protons have the same charge magnitude as electrons (but opposite sign).

The force between two protons at the same distance is also F Newton.

Explanation

Coulomb's Law most closely resembles Newton's Law of Gravitation.

• Both laws deal with forces between objects
• Both forces decrease with distance (inverse-square law)
• Mathematical formulas are similar in structure

F = k × (q1 × q2) / r^2 (Coulomb's Law)

F = G × (m1 × m2) / r^2 (Newton's Law of Gravitation)

Explanation

The magnitude of the force between two unit positive charges (each with a charge of 1 Coulomb) separated by a distance of 1 meter in a vacuum is given by Coulomb's Law:

F = k × (q1 × q2) / r^2

where:

F = force (in Newtons)

k = Coulomb's constant (approximately 8.98755 × 10^9 N m^2 C^2)

q1 and q2 are the charges (in Coulombs)

r is the distance between the charges (in meters)

Plugging in the values, we get:

F ≈ (8.98755 × 10^9 N m^2 C^2) × (1 C × 1 C) / (1 m)^2

F ≈ 8.98755 × 10^9 N

F ≈ 9 × 10^9 N (approximately)

Since 1 Newton is equal to 10^9 N (by definition), we can simplify the answer to:

F ≈ 1 N (approximately)

Explanation

In a concave mirror, the image size depends on the position of the object.

As the object moves closer to the mirror, the image size increases, and as it moves away, the image size decreases.

Explanation

• Dispersion is the optical phenomenon where white light is split into its constituent colors, also known as a spectrum.
• This occurs when light passes through a medium with a refractive index that varies with wavelength, such as a prism.

The process of dispersion involves two stages:

1. Refraction (bending of light)
2. Separation of colors (splitting into distinct colors)

The seven distinct colors that make up the visible spectrum, in order, are:

1. Red
2. Orange
3. Yellow
4. Green
5. Blue
6. Indigo
7. Violet

Explanation

When white light passes through a prism, it is refracted, or bent, and split into its individual colors, a process known as dispersion.

The order of deviation is:

• Violet (most deviated)
• Blue
• Green
• Yellow
• Red (least deviated)

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.