All Free Everyday Science MCQs with Answers

31. The most abundant element in the universe is __________.

• A. Oxygen
• B. Hydrogen
• C. Carbon Dioxide
• D. Silicon

Explanation: Hydrogen is the most abundant element in the universe, making up most of the material in stars and much of the interstellar gas. Oxygen and silicon are far less abundant cosmic elements.

32. The Sun is a __________?

• A. Star
• B. Planet
• C. Asteroid
• D. Meteor

Explanation: The Sun is a star because it produces its own light and heat through nuclear fusion. Planets and asteroids only reflect light from a star.

33. Which is the outermost planet in the solar system?

• A. Mercury
• B. Pluto
• C. Neptune
• D. Uranus

Explanation: Neptune is the outermost of the eight officially recognized planets. Pluto lies farther out at times but is classified as a dwarf planet, not a full planet.

34. Who discovered Uranus__________?

• A. William Caxton
• B. John Davise
• C. Herschel
• D. Shellay

Explanation: William Herschel discovered Uranus in 1781 while conducting telescopic observations. The other names listed are not associated with its discovery.

35. How many layers does sun have ?

• A. 6
• B. 4
• C. 7
• D. 3Chemistry

Explanation: The Sun is commonly described as having six layers: core, radiative zone, convection zone, photosphere, chromosphere and corona. The three inner regions form its interior, while the outer three are its visible atmosphere.

36. On the Moon, the escape velocity is: __________?

• A. Less than on Earth due to its lower mass and smaller radius
• B. More than on Earth due to its smaller radius
• C. The same as on Earth because escape velocity is a constant
• D. Dependent on the time of day

Explanation: The Moon’s escape velocity is about 2.38 km/s, compared with about 11.2 km/s for Earth. Its much smaller mass more than offsets its smaller radius, making escape easier.

37. Escape velocity depends on ________?

• A. Mass of the object trying to escape
• B. Radius of the planet or celestial body
• C. Both mass and radius of the planet or celestial body
• D. The velocity of the rotating planet

Explanation: Escape velocity depends on the mass and radius of the attracting celestial body, according to vₑ = √(2GM/R). It does not depend on the mass of the object trying to escape.

38. What is the escape velocity on Earth?

• A. 7.9 km/s
• B. 9.8 km/s
• C. 11.2 km/s
• D. 12.4 km/s

Explanation: Escape velocity depends on Earth’s mass and radius, not on the mass of the escaping object, and is about 11.2 km/s at the surface. The 9.8 km/s option is the value of gravitational acceleration, not escape velocity.

39. Pen and a home which will need more velocity to escape from the earth?

• A. pen needs less velocity
• B. home needs more velocity
• C. both need the same velocity
• D. none

Explanation: Ignoring air resistance, a pen and a house require the same escape velocity because escape velocity depends on the Earth’s mass and radius, not on the object’s mass. Their energies would differ, but the required speed is the same.

40. The sun completes one full rotation at its equator in how many days?

• A. 365 days
• B. 30 days
• C. 25 days
• D. 23 days

Explanation: The Sun rotates differentially, taking about 25 days to rotate once at its equator. Its rotation is slower near the poles, so 25 days is the equatorial value rather than the 365-day orbital period.