Explanation

• Power is the dot product of force and velocity.
• The formula is P = F · v = Fv cosθ, where θ is the angle between force and velocity.
• When force and velocity act in the same direction, power is P = Fv.
• The SI unit of power is the watt (W), equivalent to one joule per second.

Last verified on 28-10-2026

Explanation

• Radian is the unit of plane angle.
• It was traditionally classified as a supplementary quantity in the SI system.
• One radian is the angle subtended at the centre of a circle by an arc equal in length to the radius.

Last verified on 28-10-2026

Explanation

• The slope of a momentum–time graph represents the rate of change of momentum.
• According to Newton's second law, the rate of change of momentum is equal to the net force acting on an object.
• The relationship is F = Δp / Δt, where p represents momentum and t represents time.
• A steeper slope indicates a greater net force, while a horizontal line indicates zero net force.

Last verified on 28-10-2026

Explanation

• Mass and Length are base quantities in SI units.
• Length SI Unit: meter (m)
• Mass SI Unit: kilogram (kg)

Additional information:

Base Quantities in SI System:

• Time (second)
• Electric current (ampere)
• Temperature (kelvin)

Last verified on 16-06-2026

Explanation

• The negative of the potential gradient is equal to the electric field intensity.
• The electric field points in the direction in which electric potential decreases most rapidly.
• The mathematical relation is E = -dV/dr, where E is electric field intensity and V is electric potential.
• The negative sign indicates that electric potential decreases in the direction of the electric field.

Last verified on 28-10-2026

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