All Free Everyday Science MCQs with Answers

891. Afternoon rains in the equatorial region are the result of influences _______?

• A. Land Breeze
• B. Monsoon
• C. Frontal
• D. Convectional

Explanation: Equatorial land heats strongly during the day, causing warm, moist air to rise and cool into clouds and rain. This vertical air movement produces convectional rainfall, not frontal or land-breeze rain.

892. The largest latitude circle on earth is ________?

• A. Arctic circle
• B. Tropic of cancer
• C. Tropic of Capricorn
• D. The Equator

Explanation: The Equator is at 0° latitude and forms the largest circle around Earth. Latitude circles become progressively smaller toward both poles, so the Arctic and tropics are smaller.

893. Rainfall related to mountains is:

• A. Orographic rainfall
• B. Normal rainfall
• C. Monsoon rains
• D. Cyclonic rainfall

Explanation: When moist air is forced to rise along a mountain slope, it cools and condenses, producing orographic rainfall. The opposite, drier side is called the rain-shadow region.

894. What kind of weathering takes place on the valley side above the surface of the glacier?

• A. Plucking
• B. Abrasion
• C. Chemical weathering
• D. Frost shattering

Explanation: Valley sides exposed above a glacier commonly undergo frost shattering, as water enters cracks, freezes, expands, and breaks the rock. Plucking and abrasion are mainly erosional actions performed by moving glacial ice.

895. During a total solar eclipse the rate of Photosynthesis___________?

• A. Increase
• B. Decrease
• C. Remain Constant
• D. None of them

Explanation: During a total solar eclipse, sunlight reaching plants falls sharply, reducing the light available for photosynthesis. The rate therefore decreases temporarily.

896. Which among the following is the correct sequence of the various layers of the Atmosphere from the Earth's surface?

• A. Ionosphere, Mesosphere, Stratosphere, Troposphere
• B. Mesosphere, Stratosphere, Ionosphere, Troposphere
• C. Troposphere, Stratosphere, Mesosphere, Ionosphere
• D. Troposphere, Ionosphere, Stratosphere, Mesosphere

Explanation: The commonly taught order upward is troposphere, stratosphere, mesosphere and then the ionosphere region. The ionosphere is not a sharply separate layer because it overlaps mainly with the upper atmosphere, but option c gives the intended sequence.

897. The ozone layer is at height of________kilometers from the surface of the Earth?

• A. 10 to 20
• B. 20 to 30
• C. 30 to 40
• D. 40 to 50

Explanation: The ozone layer is concentrated mainly in the stratosphere, approximately 20 to 30 kilometres above Earth's surface. Ozone is most abundant around 15 to 35 kilometres, so this option is the standard approximate range.

898. Which vitamin is primarily produced in the skin in response to sunlight?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin K

Explanation: Ultraviolet B radiation acts on a cholesterol-related compound in the skin to begin vitamin D production. Vitamins A, C, and K are obtained mainly through diet or other body processes rather than sunlight-driven skin synthesis.

899. Which of the following is a focus area of bacteriology?

• A. Study of viruses
• B. Study of fungi
• C. Structure, genetics, and ecology of bacteria
• D. Study of parasites

Explanation: Bacteriology examines bacteria, including their structure, genetics, physiology, and ecological relationships. Virology, mycology, and parasitology instead focus on viruses, fungi, and parasites respectively.

900. What is the study of bacteria called?

• A. Virology
• B. Mycology
• C. Bacteriology
• D. Parasitology

Explanation: The study of bacteria is called bacteriology. Virology studies viruses, mycology studies fungi, and parasitology studies parasites.