Question 1

The energy value of food is measured in:

Accepted Answer

Correct Answer: Calories

Explanation: The energy value of food is measured in Calories (specifically kilocalories or kcal). One calorie is the amount of heat energy required to raise the temperature of one gram of water by one degree Celsius. Our bodies burn these calories to produce energy for movement, thinking, and maintaining body functions like heartbeat and breathing.

Question 2

Stainless Steel is an alloy of Iron, Carbon, and:

Accepted Answer

Correct Answer: Chromium

Explanation: Stainless Steel is an alloy of Iron, Carbon, and Chromium (usually at least 10.5%). The chromium reacts with oxygen to form a thin, invisible layer of chrome oxide on the surface, which prevents the steel from rusting and corroding. Nickel is also often added to improve corrosion resistance and durability.

Question 3

Which vitamin is essential for healthy eyes?

Accepted Answer

Correct Answer: Vitamin A

Explanation: Vitamin A is critical for maintaining good vision. It is a component of rhodopsin, a protein in the eyes that allows you to see in low light conditions. Deficiency in Vitamin A can lead to night blindness and Xerophthalmia (dry eyes). Foods rich in Vitamin A include carrots, sweet potatoes, and spinach.

Question 4

Which metal is used in thermometers?

Accepted Answer

Correct Answer: Mercury

Explanation: Mercury is used in thermometers because it remains liquid over a wide range of temperatures and expands uniformly with heat. Its silver color makes it easy to read against the scale. However, because mercury is toxic, modern digital thermometers or alcohol-based thermometers are becoming more common alternatives.

Question 5

What is the freezing point of water?

Accepted Answer

Correct Answer: 0°C

Explanation: The freezing point of water is 0 degrees Celsius (32 degrees Fahrenheit) at standard atmospheric pressure. At this temperature, water changes from a liquid state to a solid state (ice). Interestingly, water is most dense at 4°C, which is why ice floats on water, allowing aquatic life to survive beneath frozen lakes in winter.

Question 6

Which acid is found in Ant stings?

Accepted Answer

Correct Answer: Formic Acid

Explanation: Formic Acid (Methanoic acid) is found in the venom of ant stings and bee stings. When an ant bites, it sprays this acid into the wound, causing a burning sensation, pain, and swelling. It is the simplest carboxylic acid. The name comes from the Latin word for ant, 'formica'. Baking soda is often used to neutralize the acid.

Question 7

Optic Fibers work on the principle of:

Accepted Answer

Correct Answer: Total Internal Reflection

Explanation: Optical fibers work on the principle of Total Internal Reflection. Light signals are transmitted through thin strands of glass or plastic. When light hits the boundary of the core and cladding at a specific angle, it is reflected entirely back into the core rather than passing out. This allows data to travel long distances with minimal loss.

Question 8

Which is the smallest bone in the human body?

Accepted Answer

Correct Answer: Stapes

Explanation: The Stapes (also known as the stirrup) is the smallest bone in the human body. It is located in the middle ear and is one of the three auditory ossicles that transmit sound vibrations from the eardrum to the inner ear. It is roughly the size of a grain of rice, measuring only about 3 x 2.5 millimeters.

Question 9

The chemical formula of Ozone is:

Accepted Answer

Correct Answer: O3

Explanation: Ozone is an inorganic molecule with the chemical formula O3. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O2. While beneficial in the stratosphere (ozone layer), it is a pollutant at ground level and can cause respiratory problems.

Question 10

Which planet is the largest in our Solar System?

Accepted Answer

Correct Answer: Jupiter

Explanation: Jupiter is the largest planet in our Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets combined. It is known for its Great Red Spot, a giant storm bigger than Earth. It has a strong magnetic field and dozens of moons, including Ganymede, the largest moon in the solar system.

Question 11

Which lens is used to correct Long-sightedness (Hypermetropia)?

Accepted Answer

Correct Answer: Convex Lens

Explanation: A Convex Lens is used to correct Hypermetropia (long-sightedness), where a person can see distant objects clearly but close ones are blurry. This condition occurs when the image focuses behind the retina. The convex lens converges the light rays before they enter the eye, moving the focal point forward onto the retina.

Question 12

What is the most abundant gas in the Earth's atmosphere?

Accepted Answer

Correct Answer: Nitrogen

Explanation: Nitrogen is the most abundant gas in Earth's atmosphere, making up about 78% of the air we breathe. Oxygen makes up about 21%, and Argon consists of nearly 1%. Nitrogen is essential for life as it is a key component of amino acids (proteins) and DNA, although most organisms cannot use it directly from the air.

Question 13

Who discovered Penicillin?

Accepted Answer

Correct Answer: Alexander Fleming

Explanation: Alexander Fleming discovered Penicillin in 1928. It was the world's first true antibiotic, derived from the mold Penicillium notatum. This discovery revolutionized medicine by providing an effective treatment for bacterial infections that were previously fatal. Fleming observed that the mold killed the bacteria growing around it in a petri dish.

Question 14

Which part of the body is affected by Pneumonia?

Accepted Answer

Correct Answer: Lungs

Explanation: Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs. The air sacs may fill with fluid or pus, causing cough with phlegm, fever, chills, and difficulty breathing. It can be caused by bacteria, viruses, or fungi. It is a serious condition, especially for infants and the elderly.

Question 15

Which gas is mainly responsible for Global Warming?

Accepted Answer

Correct Answer: Carbon Dioxide

Explanation: Carbon Dioxide (CO2) is the primary greenhouse gas contributing to global warming. It is released through the burning of fossil fuels (coal, oil, gas), deforestation, and industrial processes. It traps heat in the atmosphere, leading to a rise in Earth's average temperature, melting ice caps, and changing weather patterns.

Question 16

The process of coating Iron with Zinc to prevent rusting is called:

Accepted Answer

Correct Answer: Galvanization

Explanation: Galvanization is the process of applying a protective zinc coating to steel or iron to prevent rusting. The zinc acts as a sacrificial anode; it corrodes first, protecting the underlying metal. This is commonly used in construction materials, pipes, and car bodies to extend their lifespan in outdoor environments.

Question 17

Which instrument is used to measure Humidity?

Accepted Answer

Correct Answer: Hygrometer

Explanation: A Hygrometer is an instrument used to measure the amount of water vapor (humidity) in the atmosphere, soil, or confined spaces. High humidity can make hot temperatures feel more uncomfortable, while low humidity can cause dryness. There are various types, including hair hygrometers and digital sensors.

Question 18

The chemical formula for Common Sugar (Sucrose) is:

Accepted Answer

Correct Answer: C12H22O11

Explanation: The chemical formula for Sucrose (common table sugar) is C12H22O11. It is a disaccharide composed of two monosaccharides: glucose and fructose. It is extracted primarily from sugarcane and sugar beet. When consumed, the body breaks it down into glucose and fructose to be used as energy.

Question 19

Which of the following is a good conductor of electricity?

Accepted Answer

Correct Answer: Copper

Explanation: Copper is a good conductor of electricity because it has free electrons that can move easily through the material. This allows electric current to flow with very little resistance. That is why copper is widely used in electrical wiring, motors, and electronics. Glass, plastic, and rubber are insulators.

Question 20

What is the average heartbeat rate of a healthy adult per minute?

Accepted Answer

Correct Answer: 60-100

Explanation: The normal resting heart rate for adults ranges from 60 to 100 beats per minute. A lower heart rate at rest generally implies more efficient heart function and better cardiovascular fitness. For example, a well-trained athlete might have a normal resting heart rate closer to 40 beats per minute.

Everyday Science MCQs