Free Physics in Daily Life MCQs with Answers

121. The most suitable thermometer for measuring boiling point of water is ?

• A. Mercury Thermometer
• B. Liquid crystal thermometer
• C. Bimetallic thermometer
• D. Alcohol thermometer

Explanation: A mercury thermometer is suitable for measuring water’s boiling point because mercury remains liquid well above 100°C and expands predictably. Alcohol boils near 78°C, so it cannot reliably measure the boiling point of water.

122. One mega ohm resistance is equal to ______?

• A. 106 ohm
• B. 108 ohm
• C. 107 ohm
• D. 10-6 ohm

Explanation: The prefix mega means one million, so 1 megaohm equals 1,000,000 ohms, or 10⁶ ohms. The other powers either represent different resistance values or a very small fraction of an ohm.

123. Energy possessed by water in a dam is ?

• A. Electrical energy
• B. Mechanical energy
• C. Kinetic energy
• D. Potential energy

Explanation: Water stored at height in a dam possesses gravitational potential energy because of its position. When released, this energy changes into kinetic energy and then helps generate electricity.

124. 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.

125. 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.

126. 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.

127. 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.

128. 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.

129. 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.

130. 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.