All Free Everyday Science MCQs with Answers

1601. Charge carriers in a metal are electrons rather than protons because electrons are?

• A. Smaller
• B. Negative
• C. Loosely bound
• D. All of the above

Explanation: Metallic electrons are loosely bound to their atoms and can move through the solid, whereas protons remain tightly held in atomic nuclei. Their negative charge is not the reason they conduct electricity.

1602. Photography works by?

• A. Capturing the souls of the objects being photographed
• B. Capturing light reflected from the objects being photographed
• C. Both A & B
• D. None of these

Explanation: A camera records light reflected from an object and focuses it onto film or an electronic sensor. It does not capture anything supernatural such as an object's soul.

1603. Oil rises in a wick of oil lamp on account of a property of matter is called?

• A. Angle of projection
• B. Determines
• C. Capillary action
• D. Refraction of light

Explanation: Capillary action draws the oil through the narrow spaces in the lamp wick, allowing it to reach the flame. It results from adhesive and cohesive forces in small tubes or pores.

1604. Dyne is a unit of _______?

• A. Quantity
• B. Force
• C. Pressure
• D. Depth

Explanation: The dyne is the CGS unit of force, equal to the force that gives a one-gram mass an acceleration of one centimetre per second squared. Its SI equivalent is 10⁻⁵ newton.

1605. The gas heater gives us heat by __________?

• A. Radiation
• B. Conduction
• C. Convection
• D. Environmental pressure

Explanation: A gas heater warms nearby air, which becomes less dense and rises while cooler air moves down to replace it; this circulation is convection. Radiation also contributes in some heater designs, but convection is the usual textbook answer for a room gas heater.

1606. Who discovered the law of attraction and repulsion in electric charges?

• A. Newton
• B. Gullelio
• C. Coulumb
• D. Einstein

Explanation: Charles-Augustin de Coulomb established the law describing attraction between unlike electric charges and repulsion between like charges. Newton studied gravitational attraction, not the electric-charge law.

1607. Dielectric constant of water is?

• A. 60
• B. 70
• C. 80
• D. None of these

Explanation: At ordinary temperature and low frequency, water has a relative permittivity, or dielectric constant, of about 80. This high value means water strongly reduces the electric force between charges compared with a vacuum.

1608. Mass spectrograph was Invented by?

• A. Rutherford
• B. Chadwik
• C. F.W.Aston
• D. None of these

Explanation: F. W. Aston invented the mass spectrograph and used it to identify isotopes and measure their masses. Rutherford and Chadwick made major nuclear discoveries but did not invent this instrument.

1609. With the rise in temperature, metals conductivity____________?

• A. Remains same
• B. Increases
• C. Decreases
• D. None of these

Explanation: In metals, rising temperature increases lattice vibrations, which scatter moving electrons more strongly. Electrical conductivity therefore decreases, while resistance increases.

1610. Speed of sound in water at 20 °C is___________?

• A. 1450 m/s
• B. 1474 m/s
• C. 1498 m/s
• D. 1500+ m/s

Explanation: The speed of sound in fresh water near 20 °C is approximately 1,480 m/s; many standard tables give about 1,474 to 1,482 m/s depending on the assumed water conditions. Thus 1,474 m/s is the intended closest listed value.