Free Physics in Daily Life MCQs with Answers

81. An optical instrument which is used measure the properties of visible light is called?

• A. Microscope
• B. Telescope
• C. Spectroscope
• D. Oscilloscope

Explanation: A spectroscope separates or analyses visible light according to wavelength, revealing a spectrum and often identifying substances from their lines. A microscope magnifies small objects, while a telescope collects light from distant objects.

82. Which of the following lens are useful in microscope?

• A. Convex lens
• B. Concave lens
• C. Curved lens
• D. None of These

Explanation: A compound microscope uses convex lenses because they converge light and produce magnified images. Concave lenses diverge light and are not used as the main magnifying lenses in an ordinary microscope.

83. Elastic rebound theory explains:

• A. formation of rocks
• B. structure of solids
• C. causes of earthquake
• D. None of these

Explanation: Elastic rebound theory states that rocks deform under tectonic stress and suddenly snap back when the stress exceeds their strength, releasing energy as an earthquake. It therefore explains the cause and energy release of earthquakes.

84. What is the most abundant form of matter in the universe?

• A. Plasma
• B. Liquid
• C. Gas
• D. Solid

Explanation: Most ordinary matter in the visible universe is plasma, including stars, because extreme heat strips electrons from atoms. Plasma is therefore distinct from the solid, liquid and neutral-gas states listed.

85. Bolometer measures: ____________?

• A. Breadith of tree
• B. Burning capacity
• C. Heat radiation
• D. Bearing capacity

Explanation: A bolometer detects and measures radiant energy by sensing the temperature change produced when radiation is absorbed. It is especially used for measuring heat radiation.

86. Mohus scale is used for to measure ____________?

• A. Hardness
• B. Humidity
• C. Pressure
• D. Temperature

Explanation: The Mohs scale ranks minerals by scratch resistance, from talc at 1 to diamond at 10. It measures relative hardness, not humidity, pressure or temperature.

87. Which amongst the following cannot pass through vacuum?

• A. Light
• B. Radiation
• C. Sound
• D. None of These

Explanation: Sound is a mechanical wave and needs particles of a medium, such as air, water or a solid, to carry its vibrations. Light and other electromagnetic radiation can travel through a vacuum.

88. Night vision is possible with the help of ___________?

• A. Red light
• B. Violet light
• C. Infrared Rays
• D. Ultra violet Light
• E. None of these

Explanation: Infrared radiation is used by many night-vision devices because it can be detected in darkness and is often emitted or reflected by warm objects. Red light may preserve dark adaptation but is not the basis of infrared night vision.

89. A fathom is equal to ________feets?

• A. 6
• B. 5
• C. 4
• D. 3

Explanation: A fathom is an old nautical unit of length equal to 6 feet, or about 1.83 metres. It is commonly used to state water depth.

90. What is a Geiger Counter used to measure?

• A. Radioactivity
• B. Pressure
• C. Water flow
• D. None of these

Explanation: A Geiger counter detects and counts ionising radiation, such as alpha, beta and gamma radiation, using a Geiger-Müller tube. It is therefore used to indicate radioactivity rather than pressure or water flow.