Explanation

• Charles' Law states that the volume of a fixed amount of gas is directly proportional to its absolute temperature when pressure remains constant.
• The formula is V1 / T1 = V2 / T2, where temperature is measured in Kelvin.
• When the temperature increases, the gas volume increases; when the temperature decreases, the volume decreases, provided the pressure remains constant.

Last verified on 28-10-2026

Explanation

• The capacitance of a parallel-plate capacitor is directly proportional to the plate area and inversely proportional to the distance between the plates.
• Doubling the plate area doubles the capacitance, while halving the distance doubles it again.
• Therefore, the new capacitance becomes 2 x 2 = 4 times the original capacitance.
• The formula is C = εA / d, where A is plate area, d is the separation, and ε is the permittivity of the material between the plates.

Last verified on 28-10-2026

Explanation

• The electric field lines of a positive point charge point outward, away from the charge.
• As we move farther away from the charge, the electric field strength decreases according to the inverse-square law.
• The electric field strength is given by E = kQ / r^2, where Q is the charge and r is the distance from it.

Last verified on 28-10-2026

Explanation

• Surface tension causes a liquid drop to minimize its surface area, making it tend toward a spherical shape.
• Surface tension arises due to the cohesive forces between liquid molecules at the surface.

Last verified on 28-10-2026

Explanation

• An ammeter measures the electric current flowing through a circuit.
• It is connected in series so that the same current flowing through the circuit also passes through the ammeter.
• An ammeter has very low resistance to minimize its effect on the current being measured.

Additional information:

• A voltmeter, in contrast, is connected in parallel to measure the potential difference across a component.

Last verified on 28-10-2026