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 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

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

Dentists use concave mirrors to illuminate inaccessible places in the tooth.

The concave shape of the mirror allows it to reflect light and images from small, hard-to-reach areas.

Such as the back of the mouth or between teeth.

Explanation

Lenses form images through Refraction.

It bends light to focus it on a point, creating an image.

Explanation

Long-sightedness is also known as hyperopia.

It is a vision defect where the image is formed beyond the retina, rather than directly on it.

This occurs when the eyeball is too short or the cornea is too flat, causing light to focus at a point behind the retina.

As a result, close objects appear blurry, while distant objects may remain clear.