Explanation

• In a transformer, the frequency of AC remains the same in both the primary and secondary coils.
• The voltage can increase or decrease depending on the turns ratio of the coils.

Last verified on 28-10-2026

Explanation

• The relation between time period (T) and orbital radius (r) is: T² ∝ r³
• This is given by Kepler's Third Law - The Law of Periods.

Last verified on 28-10-2026

Explanation

• Pascal's law states that a change in pressure applied to an enclosed fluid is transmitted equally and undiminished throughout the fluid and to the walls of its container.
• The pressure is transmitted in all directions, not just in the direction of the applied force.
• This principle is used in hydraulic brakes, hydraulic lifts, and hydraulic presses.
• Pressure is calculated as P = F / A, where F is force and A is the area over which the force acts.

Last verified on 28-10-2026

Explanation

• A voltmeter measures potential difference (voltage) between two points in a circuit.
• To do this correctly, it must be connected in parallel with the component across which the voltage is to be measured.

Last verified on 28-10-2026

Explanation

Energy stored in a capacitor:

U = 1/2 C V^2

U is directly proportional to V^2.

If V' = 2V

U' = 1/2 C (2V)^2 = 4 x 1/2 C V^2 = 4U

Answer: Four times the initial value.

Last verified on 28-10-2026