Explanation

• Translatory motion is the motion in which all parts of a body move the same distance in a straight line or along a path.

Examples include:

• Linear motion – straight-line movement
• Vibrational motion – repeated back-and-forth movement along a line
• Oscillatory motion – motion to-and-fro about a fixed point

Rotatory motion involves rotation about an axis, so it is not translatory.

Last verified on 10-02-2026

Explanation

• The power of a lens (P) is given by the formula:
• P = 100/f (cm) or P = 1/f (m)
• Focal length (f) and power (P) are inversely proportional.
• So, if the focal length increases, the power decreases.

Additional information:

• Convex lens: Converging lens
• Unit of power: Diopter (D)

Last verified on 10-02-2026

Explanation

• Pressure is a fundamental physical quantity that is defined as the force exerted per unit area.
• It is a measure of the strength of a force acting on a surface.
• It is typically measured in units such as Pascals (Pa) or pounds per square inch (PSI).

Last verified on 10-02-2026

Explanation

• The equilibrium constant (Kc) measures the ratio of product concentrations to reactant concentrations at chemical equilibrium.
• It is expressed in terms of molar concentrations (moles per liter, M).
• Used in chemical reactions in solution to predict the direction and extent of reactions.

Last verified on 09-02-2026

Explanation

• Distance: Total path traveled by the car along the route
• Displacement: Shortest straight-line distance between start and end points
• Since Ali returned to the starting point, displacement = 0

Last verified on 08-02-2026

Explanation

• When the angle θ between force (F) and displacement (d) is 90°, cos90° = 0.
• Therefore, Work Done (W) = 0.

Additional information:

• Example: Carrying a bag horizontally while the force is vertical → no work is done.
• Work is maximum when force is along the displacement (θ = 0°).

Last verified on 08-02-2026

Explanation

• Cause: Primarily due to excess greenhouse gases like CO₂, CH₄, and N₂O from human activities.
• Effects: Rising temperatures, melting glaciers, extreme weather, and sea-level rise.

Last verified on 08-02-2026

Explanation

• Instrumental error occurs when measuring devices give consistently higher or lower readings.
• All measurements are systematically off by a fixed amount.
• Caused by faulty instruments, calibration issues, or worn-out equipment.
• Can be corrected by calibrating instruments.

Last verified on 07-02-2026

Explanation

Scalar quantities are physical quantities that have only magnitude (amount or size) but no direction.

Examples of scalar quantities include:

• Mass
• Temperature
• Time
• Energy
• Distance

Last verified on 07-02-2026

Explanation

The Earth was formed about 4.5 billion years ago.

Additional information:

• Method Used: Radiometric dating
• Oldest Materials: Meteorites and ancient Earth rocks
• Scientific Consensus: Supported by geology and astronomy

Last verified on 16-01-2026