All Free Everyday Science MCQs with Answers

1641. State of matter which has definite shape and volume is called __________?

• A. Liquid
• B. Gas
• C. Solid
• D. None of these

Explanation: A solid has particles held closely in fixed positions, giving it both a definite shape and a definite volume. Liquids have a fixed volume but take the shape of their container, and gases have neither.

1642. The quantity of matter in an object is its ________?

• A. Force
• B. Mass
• C. Weight
• D. None of these

Explanation: Mass is the quantity of matter in an object and is measured in kilograms. Weight is the gravitational force acting on that mass, so it can change with gravity while mass remains constant.

1643. Lambert's law is related to?

• A. Reflection
• B. Refraction
• C. Interference
• D. Illumination

Explanation: Lambert’s law is used in photometry and illumination to describe how the illumination of a surface varies with the angle of incident light. It is therefore associated with illumination, not reflection, refraction or interference.

1644. The time period of a pendulum when taken to the Moon would?

• A. remain the same
• B. decrease
• C. become zero
• D. increase

Explanation: A pendulum’s period is proportional to the inverse square root of gravitational acceleration. Since the Moon’s gravity is weaker than Earth’s, the pendulum swings more slowly and its period increases.

1645. Intensity of gravitational field of earth is maximum at?

• A. Poles
• B. Equator
• C. Center of earth
• D. Surface

Explanation: Earth’s gravitational field is strongest at the poles because the polar surface is slightly closer to Earth’s center and centrifugal reduction is smallest there. It is weakest at the equator and zero at the idealized center.

1646. Angle of friction and angle of repose are?

• A. equal to each other
• B. not equal to each other
• C. proportional to each other
• D. None of these

Explanation: At the limiting condition of motion, the angle of friction and the angle of repose are equal because both have tangent equal to the coefficient of friction. The angle of repose is the slope angle at which a body just begins to slide.

1647. According to the theory of relativity, which of the following always remains constant ?

• A. Length of an object
• B. Time
• C. Space
• D. Velocity of light

Explanation: Special relativity treats the speed of light in vacuum as invariant for all inertial observers. Length, time, and space measurements can vary with the observer’s motion, so they are not always constant.

1648. Freezing point of water at Fahrenheit Scale is?

• A. 0 °F
• B. 212 °F
• C. 32 °F
• D. -32 °F

Explanation: Water freezes at 32 °F, which corresponds to 0 °C. The 212 °F value is its boiling point at standard atmospheric pressure.

1649. Velocity of sound in air does not change with the change of?

• A. Temperature of air
• B. Pressure of air
• C. Moisture content in air
• D. Wind in the direction of propagation of sound

Explanation: At a fixed temperature, sound speed in an ideal gas is essentially independent of air pressure because both density and pressure change proportionally. Temperature, humidity and wind can affect the speed measured relative to the ground or the medium.

1650. The weakest of all fundamental forces is the ________________?

• A. Gravitational force
• B. Electrostatic force
• C. Magnetic force
• D. Nuclear force

Explanation: Gravity is the weakest fundamental interaction, although it dominates astronomical structures because masses are always attractive and cannot cancel. The strong nuclear force is the strongest, while electromagnetic force is much stronger than gravity.