All Free Everyday Science MCQs with Answers

1541. Which from the following is true for "Sound"?

• A. Sound cannot travel through a vacuum
• B. Sound cannot travel through gases
• C. Sound cannot travel through liquids
• D. Sound cannot travel through solids

Explanation: Sound is a mechanical wave, so it needs particles of a medium to carry its vibrations and cannot travel through a vacuum. It can travel through gases, liquids and solids.

1542. A camera uses a __________ to form an image.

• A. convex lens
• B. concave lens
• C. condenser lens
• D. none of these

Explanation: A camera uses a converging convex lens to focus reflected light and form a real image on its film or electronic sensor. A concave lens diverges light and cannot normally form this image by itself.

1543. The SI unit of "pressure" is _________.

• A. pascal
• B. joule
• C. tesla
• D. henry

Explanation: The pascal is the SI unit of pressure and equals one newton per square metre. Joule measures energy, tesla measures magnetic flux density, and henry measures inductance.

1544. Radioactivity was discovered by __________?

• A. Kelvin
• B. Thomson
• C. Rutherford
• D. Bacquerel

Explanation: Henri Becquerel discovered radioactivity in 1896 while investigating uranium salts. Rutherford later studied the nature of radioactive emissions, but he was not the discoverer of radioactivity.

1545. For a fixed mass of gass at constant temperature, if we decrease volume, the pressure will _________?

• A. also decrease
• B. increase
• C. remains constant
• D. none of these

Explanation: Boyle’s law states that pressure is inversely proportional to volume at constant temperature, so reducing the volume increases the pressure. This applies to a fixed amount of gas.

1546. 'Magnetometer' is used to measure: ______________?

• A. Air Pressure on Ships
• B. Electromagnetic Force in Space Devices
• C. Changes in the Earth's Magnetic Field
• D. Changes in Oceanic Current

Explanation: A magnetometer detects the strength and direction of magnetic fields, including changes in Earth’s magnetic field. It is not primarily an instrument for measuring air pressure or ocean currents.

1547. Which one of the following of glass can cut ultraviolet rays?

• A. Jena Glass
• B. Soda Glass
• C. Pyrex Glass
• D. Crookes Glass

Explanation: Crookes glass contains compounds that strongly absorb ultraviolet radiation and was used in protective eyewear. Ordinary soda glass transmits or only partly absorbs some ultraviolet wavelengths rather than providing this specialized cutoff.

1548. BTU is a unit of________?

• A. Force
• B. Magnetic flux
• C. Energy
• D. None of these

Explanation: A British thermal unit, or BTU, is a unit of heat energy, historically defined as the heat needed to raise one pound of water by one degree Fahrenheit. It is not a unit of force or magnetic flux.

1549. In an atomic nucleus, neutrons and protons are held together by: ___________?

• A. Gravitational forces
• B. Exchange forces
• C. Coulombic forces
• D. Magnetic forces

Explanation: Protons and neutrons are bound inside the nucleus by the strong nuclear interaction, often described in older texts as an exchange force involving exchange particles. Gravity is far too weak at nuclear distances, while electric repulsion acts between protons.

1550. According to Quark theory, there are _________ elementary particles.

• A. Three
• B. Six
• C. Nine
• D. Ten

Explanation: The quark model recognises six quark flavours: up, down, charm, strange, top and bottom. They combine to form composite particles such as protons and neutrons.