Free Scientific Reasoning MCQs with Answers

• A. Meat from mountainous animals is stronger than animals on the ground level.
• B. The boiling point of water is lower at higher altitudes.
• C. Pathogens and pollutants in urban cities cause the meat to rot a bit before we begin to cook it.
• D. None of the above

Explanation: Because water boils at a lower temperature at higher elevations, foods that are prepared by boiling or simmering will cook at a lower…

• A. To prevent someone from bumping into them and hurting themselves
• B. So that the cool air can efficiently circulate and cool the entire room
• C. To set up convection currents to cool the room since the cool air is denser and settles down
• D. It's just a standard, you can place the units anywhere you like

Explanation: Air-conditioning units are installed on the upper side of a room to facilitate effective cooling through convection currents.

• A. Water has a high specific heat capacity so does not heat up or cool down easily.
• B. Water reflects more light than buildings and land
• C. Water evaporates to give cloud cover
• D. Water extinguishes the Sun.

Explanation: The high heat capacity of water also explains why the temperatures of land near a body of water are more moderate.

• A. Aquatic organisms produce antifreeze proteins that prevent their bodies from freezing.
• B. In water bodies, the top layer freezes, forming an insulating layer, allowing aquatic life to survive beneath it.
• C. Aquatic life migrates to warmer parts of the water body to escape freezing temperatures.
• D. They perish in winter but leave behind resilient eggs to hatch in spring.

Explanation: The correct answer is that only the top layer of a water body freezes, creating an insulating barrier that keeps the water below from…

• A. The greenhouse effect is named for the environmental goal of planting more trees to combat global warming.
• B. The greenhouse effect is named because it describes the process by which greenhouse gases trap heat, similar to how a greenhouse's glass structure traps heat.
• C. The term was coined by a scientist who had a preference for the color green.
• D. None of the above options accurately describes the origin of the term 'greenhouse effect.'

Explanation: The term 'greenhouse effect' is used because Earth's atmosphere acts in a manner similar to a greenhouse.

• A. The fast-moving train creates a strong air pressure that can pull you towards it, risking serious injury.
• B. The train's speed might make you feel dizzy, potentially causing you to faint.
• C. Objects falling from the train could hit you due to the train's high velocity, causing injury.
• D. There is no real danger; it's just a safety guideline.

Explanation: When you stand close to a fast-moving train, the train's rapid movement creates a lower air pressure between the train and the person…

• A. The slippery nature of the soap causes the germs to slip off
• B. The soap traps germs and dirt and is washed off with them
• C. The soap disintegrates grease on the skin due to its non-polar tail
• D. The soap produces free radicals which destroy the germs on our hands

Explanation: Soap works through its molecular structure, which consists of a hydrophobic (non-polar) tail and a hydrophilic head.

• A. Heated in a vacuum
• B. Distilled from a solution
• C. Reacts with a liquid
• D. Melted

Explanation: The assembled apparatus is specifically used for a reaction where a solid reacts with a liquid, producing a gas that is subsequently…

• A. 30 degrees
• B. As less of an angle as possible
• C. 45 degrees
• D. 90 degrees

Explanation: The range (x) for an angle theta is given by the following: For x to be the largest, cos θ sinθ should be the largest.

• A. 1
• B. 2
• C. 3
• D. 4

Explanation: The ball moves in a tangential direction when released because the centripetal force is no longer acting on it.

• A. Nuclear fission
• B. Condensation
• C. Reduction
• D. Combustion

Explanation: Nuclear fission involves the greatest change in energy as indicated by the amount of energy released which is used to run nuclear power…

• A. Removing sodium chloride from water
• B. Boiling water
• C. Lighting a matchstick
• D. Increasing the height of a ball from the ground to an elevated table

Explanation: A spontaneous reaction is one that proceeds on its own once initiated. Lighting a matchstick is spontaneous after the initial ignition…

• A. Dust sticks to the rust in fans
• B. The momentum of the fan is so high that the dust particles which have low inertia are instantly caught in the motion of the blades and adopt the motion of the blades
• C. The dust settles in and sticks to fans when they are not moving
• D. The electrostatically charged fan blades attract dust particles

Explanation: The correct answer is that the electrostatically charged fan blades attract dust particles.

• A. III>I>IV>II
• B. II>III>IV>I
• C. I>III>IV>II
• D. I>II>III>IV

Explanation: To obtain dry iron, we first hold a magnet above the mixture. We then mix the remaining salt and sand into water.

• A. The magnet of the television screen attracts the magnetic hair
• B. The electrostatically charged television screen induces a charge on our hair and attracts it.
• C. The television screens have a glue which makes our hair stick to them
• D. We get goosebumps from standing that close to a screen as part of a reflex action

Explanation: Following use, TV screens attain an electrostatic charge which induces a charge on our hair and attracts it.

• A. The hair clings to the fibers in the cap causing them to be disoriented
• B. None of the above
• C. Sudden exposure to increased sunlight damages the hair
• D. The electrostatic interactions between the hair and the cap cause the hair to become messy

Explanation: friction between the cap and hair yields electrostatic charges leading to the hair being attracted to the cap and as a result, becoming…

• A. Carrying a box to a different room
• B. Pushing a box
• C. Pulling a box using a string
• D. Lifting a box from the ground

Explanation: Work is defined as the component of the force parallel to the displacement multiplied by the magnitude of the displacement.

• A. Jack carrying a bucket of water along a horizontal road
• B. A skydiver falling with uniform velocity towards the ground
• C. Sarah walking up the staircase
• D. Asad swinging a marble tied to a string at uniform speed

Explanation: Work is defined as the force applied on an object causing displacement in the direction of the force.

• A. Pulling a rubber band
• B. Climbing a ladder
• C. A carton sliding on a frictionless horizontal floor
• D. A phone thrown down from the balcony

Explanation: Since there is no frictional force, and the carton is experiencing no other net force, no work can be done

• A. Afsana = 15cm, Sara= 40cm
• B. Afsana = 20cm, Sara = 3cm
• C. Afsana = 40cm, Sara = 15cm
• D. Afsana = 40cm, Sara = 52cm

Explanation: So, Afsana is 40 cm away from the midpoint, and Sara is 52 cm away from the midpoint.Since the seesaw is 2m (200 cm) long, the midpoint is…