Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology
  1. What term do we use for the average distance between Sun and Earth?

  1. Astronomical Unit

  2. Astronomy Unit

  3. Light Year

  4. none
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The astronomical unit (AU) is the standard unit of measurement for the average distance between the Earth and Sun, approximately 93 million miles or 150 million kilometers. It is used primarily for measuring distances within the solar system, distinguishing it from light-years used for interstellar distances.

Multiple choice general knowledge science & technology

How old is the earth?

  1. 5,000,000 years

  2. 5,000,000,000 years

  3. 50,000,000,000 years

  4. No one knows
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Scientific evidence, including radiometric dating of meteorites and Earth's oldest rocks, indicates Earth is approximately 4.5 billion years old. Option B (5 billion) is the closest approximation among the choices, though slightly high. Earth formed from the solar nebula around 4.54 billion years ago.

Multiple choice general knowledge science & technology
  1. To reach another planet, a spacecraft must be aimed:

  1. At the planet

  2. Midway between the two

  3. Where the planet will be when the spacecraft reaches it

  4. all the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A spacecraft must be aimed at where the planet will be when the spacecraft arrives, not where it is now. Both the spacecraft and target planet are moving in their orbits, so you must calculate the planet's future position at arrival time. Aiming at the planet's current position would cause the spacecraft to arrive where the planet used to be. 'Midway' makes no sense for intercept trajectories.

Multiple choice general knowledge science & technology

Why does one sometimes have red-eyes in photographs?

  1. The rays of the sun bounce off the lens of the camera, projecting a reddish glow into the eyes of those photographed.

  2. An ineffective flash doesn't allow enough light for the actual eye color to be recorded in the photo.

  3. A flash that is too glaring often makes people blink at the same time the shutter snaps. Therefore, the subjects eyes are merely blurred, though it appears red in the actual photo.

  4. The pupil doesn't have enough time to constrict and the picture records the reflection of the red retina in the back of the eye.

  5. I don't know
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The red-eye effect occurs because the camera flash is too fast for the pupil to constrict. The light enters the dilated pupil, illuminates the retina (which is rich in blood vessels and appears red), and reflects back to the camera. The other options are incorrect - sun rays aren't relevant, flash effectiveness isn't the issue, and blinking causes blur, not red-eye. Option E is not the scientific explanation.

Multiple choice general knowledge science & technology

It is estimated that there are about 100 occurrences of lightning throughout the world each second. How many of these strike ground?

  1. 75

  2. 50

  3. 25

  4. 5
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to meteorological studies, about 25% of lightning strikes (approximately 25 out of 100 per second globally) actually hit the ground. The rest are cloud-to-cloud lightning or don't reach the earth's surface. Lightning occurs approximately 100 times per second worldwide, but only a quarter of these are ground strikes. The other options (75, 50, 5) don't match the scientific consensus.

Multiple choice general knowledge science & technology

What would happen if you soaked a raw egg in vinegar for 24 hours?

  1. The yolk would turn green

  2. It would disintegrate completely

  3. The shell would turn rubbery

  4. The shell would split perfectly in two
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When you soak an egg in vinegar, the acetic acid reacts with the calcium carbonate in the eggshell, dissolving it over 24 hours. This leaves the egg with just the membrane, making it feel rubbery and bouncy. The yolk doesn't change color, it doesn't disintegrate, and the shell doesn't split cleanly - it gradually dissolves. This is a classic kitchen chemistry experiment.

Multiple choice general knowledge science & technology

Why does your voice sound different to you on a recording?

  1. When you hear yourself speak regularly, the sound waves emanate through the tissue, bone, and other material, which changes its sound.

  2. When you hear yourself speak regularly, the sound waves bounce off who you are talking to, which changes its sound.

  3. The speakers of the cassette recorder distort the sound of your recorded voice.

  4. I don't know
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When you speak, you hear your voice through two pathways: air conduction (sound waves through air) and bone conduction (vibrations through skull bones). Bone conduction enhances lower frequencies, making your voice sound fuller to yourself. A recording only captures the air-conducted sound, which lacks this bass boost and thus sounds thinner and higher-pitched.

Multiple choice general knowledge science & technology

You are sitting in a baseball game in bleachers far from the field. You see the batter hit the ball and then you hear the crack of the bat. Why the delay?

  1. The sound has to travel through a lot of material (all the people in the stadium) before it reaches your ear.

  2. Light travels almost one million times faster than sound.

  3. Your brain anticipates what is going to happen visually, so you see the act a split second before it actually happens.

  4. You are too far away to hear the actual sound of the bat hitting the ball. What you hear is the echo of the actual sound.

  5. I don't know
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Light travels at approximately 300,000 kilometers per second, while sound travels at only 343 meters per second in air. This means light is nearly one million times faster than sound. When you're far from the action, the light arrives almost instantly, but the sound takes noticeable time to travel the same distance.

Multiple choice general knowledge science & technology

What are mirages?

  1. Hallucinations of dehydrated wanderers

  2. A mixture of gases that leak through fissures in the earth, mixing to create strange apparitions

  3. Miniature whirlwinds blow sand in tight circles that seem to take shape from a distance

  4. Optical phenomenon due to temperature differences of the surface and air directly above the surface

  5. Low lying clouds

  6. I don't know
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Mirages are optical phenomena caused by temperature gradients in air near a hot surface (like sand or pavement). Hot air near the ground is less dense than cooler air above, creating a refractive index gradient that bends light rays. This bending can create the illusion of water or make distant objects appear displaced or inverted.

Multiple choice general knowledge science & technology

Why is the moon small when it is high overhead in the sky, and large when it is near the horizon?

  1. Near the horizon, the brain scales the size of the moon to trees and buildings.

  2. The moon is actually much closer when it is near the horizon, and thus appears larger.

  3. The physical act of rolling the eyes upwards (towards the sky) encourages the brain to interpret objects to be smaller than they are.

  4. When the moon is viewed near the horizon, one is actually viewing its reflection against the earth's ozone layer. This image is a shrunken version of the actual moon.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The moon illusion is a psychological phenomenon where the moon appears larger near the horizon. This occurs because the brain compares the moon's size to foreground objects like trees and buildings when it's low, making it seem larger. When the moon is high overhead, there are no reference objects, so it appears smaller despite being the same angular size.