Scientific Reasoning MCQs

Question 1

Pluto has a diameter of just 1,438 miles. It is made mostly of ice and frozen rock. It is very small and has an irregular orbit. It was originally classified as the ninth planet from the Sun, but it has been recategorized as a dwarf planet within the Kuiper belt. Which of the following is not a factual detail about Pluto?

Accepted Answer

Pluto should be classified as a dwarf planet.

Answer

Pluto has a diameter of 1,438 miles.

Answer

Pluto is made mostly of ice and frozen rock.

Answer

Pluto has an irregular orbit.

Question 2

Objects are attracted to one another by the force of gravity. Gravity is proportional to the mass-the amount of matter-objects have; gravity decreases as the distance between the objects increases. An object's weight is a measurement of the Earth's gravitational pull on the object. What happens to the mass and weight of a rocket as it travels beyond Earth's orbit?

Accepted Answer

Its mass remains the same, and its weight decreases.

Answer

Its mass remains the same, and its weight increases.

Answer

Its mass increases, and its weight remains the same.

Answer

Its mass decreases, and its weight decreases.

Question 3

You run an experiment to test which brand of food your dog prefers. You offer her three different brands of food at each meal, presenting them all at the same time (so that she does not just prefer the one that comes first!). Three weeks of data collection indicate that she ate Brand C more often than Brand A or Brand B. What can you conclude from these results?

Accepted Answer

Your dog preferred Brand C but you do not know why

Answer

Brand B was her second favorite food

Answer

Brand C is the healthiest food

Answer

Brand B and Brand A taste bad

Answer

Brand C is the cheapest food

Question 4

"The World Health Organisation has recorded 184 human cases of the H5N1 strain of bird flu, all of them caused by contact with infected birds. That 103 of these have resulted in death indicates how dangerous this virus is, and no vaccine has yet been developed. For there to be a worldwide epidemic of H5N1 amongst humans, it would have to be possible for the virus to be passed easily from one person to another. Unlike normal influenza, H5N1 can only bind to receptors deep in the lungs. As a result, it cannot multiply in the upper respiratory system and thereby be transmitted by sneezing and coughing. So it cannot be transmitted easily between people. Influenza viruses can mutate, and thus possibly change the way in which they infect victims." Which of the following can be drawn as a conclusion from the passage above?

Accepted Answer

If H5N1 mutates, there is likely to be a worldwide epidemic amongst humans of this strain of bird flu.

Answer

Unless a vaccine is developed, many more people will catch the H5N1 strain of bird flu.

Answer

If a person has no contact with birds, they are unlikely ever to catch the H5N1 strain of bird flu.

Answer

Unless H5N1 mutates, a worldwide epidemic amongst humans of this strain of bird flu is unlikely.

Answer

None of the above

Question 5

A ballet dancer of mass 80 kg and a wingspan of 80cm is executing a spin. She then folds her arms and brings them to within 20 cm from the central axis of her body. If she was initially making 3 rotations per second, how many does she make now?

Accepted Answer

48 rotations per second

Answer

35 rotations per second

Answer

15 rotations per second

Answer

6 rotations per second

Question 6

The small gear has 10 teeth and the big gear has 50 teeth. When the small gear rolls around the big gear, how many times will the arrow return to its initial orientation (pointing upward)?

Accepted Answer

6 times

Answer

5 times

Answer

10 times

Answer

8 times

Question 7

An observer on the ground sees an eagle flying towards thep east at 15m/s chasing a hummingbird flying at 5 m/s. He approximates that the mass of the eagle is 4 times that of the hummingbird. If the eagle catches the hummingbird and continues to fly with the same thrust from its wings, what speed with the observer see them moving at?

Accepted Answer

13m/s

Answer

10m/s

Answer

16m/s

Answer

7m/s

Question 8

Why is the pupil of the human eye black?

Accepted Answer

The pupil is a hole that allows light to enter, and it appears black because the light is absorbed or scattered inside the eye.

Answer

The pupil appears black because it is made of dark-colored tissues.

Answer

The pupil can appear in different colors depending on the light conditions.

Answer

The vitreous humor behind the pupil is black, causing the pupil to appear black.

Question 9

Why does the burning of a tire yield black smoke while burning stoves in homes rarely produce smoke?

Accepted Answer

Combustion of heavy fuels like tires results in incomplete combustion, producing elemental carbon that appears as black smoke.

Answer

Burning tires release particles that break off due to heat and create the appearance of black smoke.

Answer

The heat from the fire melts tires and the evaporated material contributes to black smoke.

Answer

None of the above options are correct.

Question 10

When driving a car around a corner, why do we feel as if we are thrown away from the corner?

Accepted Answer

Your inertia wants you to keep moving in a straight line.

Answer

There is a force acting on you away from the center of the turn called centrifugal force which gives this feeling.

Answer

Your body offers a reaction force to the centripetal force of the turn away from the center.

Answer

The turn causes a pressure difference on either side of the car which causes you to move towards the region of low pressure which is away from the center of the curve.

Question 11

The figure shows a table where some cutlery is placed on top of a table cloth. When the table cloth is pulled quickly, it is possible that the cutlery lands directly on the same spot on the table and does not get carried away with the cloth. Which of the following serves as a reasonable explanation?

Accepted Answer

The quick pulling action combined with the cutlery's inertia prevents any substantial movement of the cutlery.

Answer

The rapid pulling of the table cloth causes the plates and cloth to become charged with static electricity. This repulsion of like charges creates a levitation force that subtly lifts the cutlery.

Answer

The cloth is slippery and offers no friction, allowing it to be easily pulled out from under the cutlery.

Answer

The cutlery remains in the same position due to the gravitational force holding it down.

Question 12

The carpet moves while the dust particles remain stationary due to inertia, causing a separation of dust from the carpet. Why does this happen?

Accepted Answer

The carpet's motion is resisted by the dust particles' inertia, causing the dust to separate.

Answer

The carpet exerts a reaction force on the dust particles, pushing them off.

Answer

The friction from beating charges the carpet, causing it to repel the dust.

Answer

None of these explanations are correct.

Question 13

Why do satellites not come falling down to Earth due to gravity?

Accepted Answer

They are continually falling towards Earth but move forward fast enough to maintain a stable orbit

Answer

The gravitational pull of the Sun counteracts Earth's gravity, keeping satellites in orbit

Answer

The balance between gravitational pull and centrifugal force keeps satellites in their orbit

Answer

They rely on onboard propulsion systems to stay in orbit

Question 14

The speed at which neurons conduct nerve impulses depends upon the rate of diffusion of sodium and potassium ions as well as on the resistance of the nerve fibers. Why do myelinated axons of frogs, having a diameter of 3.5µm conduct impulses at speeds of 30ms-1 whereas myelinated axons of the same diameter in a cat, conduct impulses at speeds of 90ms-1?

Accepted Answer

Cats are warm-blooded whereas frogs are cold-blooded

Answer

Concentration gradients of potassium and sodium are steeper in cats

Answer

The cats have more neurons transmitting the same signal

Answer

Neurons in cats have smaller refractory periods

Question 15

Why is color blindness more common in males than in females?

Accepted Answer

Color blindness is a sex-linked genetic disorder

Answer

Men do not take care of their eyes well enough

Answer

Men spend more time in front of digital screens than women

Answer

Men usually aren't able to distinguish between colors due to some circuitry in their right hemisphere of the brain

Question 16

Which bacteria are responsible for the formation of curd?

Accepted Answer

Lactobacillus acidophilus

Answer

Lactic acid bacteria

Answer

Bacillus radicicola

Answer

Lactobacillus aureus

Question 17

Why does the Sun appear red at sunset and sunrise?

Accepted Answer

During sunset, the sun's rays travel through more atmosphere, scattering shorter wavelengths and leaving red light to dominate.

Answer

The Sun emits different colors from different areas, and at sunset, we see the red part.

Answer

The Sun's nuclear reactions change intensity at sunset, altering its color to red.

Answer

Plants emit red pigments at sunset, which color the sky red.

Question 18

How much does the sky weigh?

Accepted Answer

5.2 million billion metric tons

Answer

12 billion kilograms

Answer

1000 kilograms

Answer

The sky does not have weight

Question 19

What would be the total weight of all humans on Earth combined, approximately, if the average weight of a human is 40 kg and the population is 8 billion?

Accepted Answer

320 billion kg

Answer

7 billion kg

Answer

320 million kg

Answer

2 billion kg

Question 20

Honey is sweeter than cane sugar or corn syrup. Which one of the following carbon sugars is responsible for this

Accepted Answer

Fructose

Answer

Lactose

Answer

Sucrose

Answer

Dextrose

Free Scientific Reasoning MCQs with Answers