Science Quiz For Class 6 With Answers

Explanation
The SI unit of speed is meters per second (m/s). This unit represents the distance traveled in meters divided by the time taken in seconds. It is commonly used in scientific and engineering calculations to measure the rate at which an object or person is moving. The m/s unit allows for precise and consistent measurements, making it the standard unit for speed in the International System of Units (SI).

Explanation
Photosynthesis is the correct answer because it is the process by which plants convert sunlight, water, and carbon dioxide into glucose and oxygen. During photosynthesis, plants use chlorophyll in their leaves to capture sunlight energy, which is then used to convert water and carbon dioxide into glucose. This process is essential for plants to produce their own food and release oxygen into the atmosphere. Transpiration is the process of water movement through a plant, translocation refers to the movement of sugars and other nutrients within a plant, and perspiration is the process of sweating in animals.

Explanation
Plants do not have lungs like animals, but they do have a process called respiration. Through tiny openings called stomata, plants take in carbon dioxide and release oxygen. This process is essential for their survival, as it provides them with the energy they need to grow and carry out other metabolic activities. Therefore, the statement "Plants do not breathe" is false.

Explanation
The solar cell receives energy from sunlight. Sunlight is the primary source of energy for solar cells as they convert sunlight into electricity through the photovoltaic effect. However, solar cells can also generate electricity from artificial light sources such as incandescent or fluorescent bulbs. These artificial light sources emit photons that can be absorbed by the solar cell's semiconductor material, allowing for the generation of electricity.

Explanation
There are eight planets in our solar system. This is based on the traditional definition of a planet, which includes Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto, which was previously considered the ninth planet, was reclassified as a dwarf planet in 2006. Therefore, the correct answer is 8.

Explanation
The moon is considered a satellite because it orbits around a larger celestial body, which in this case is the Earth. Satellites are objects that revolve around a planet or a star, and the moon fits this definition as it constantly orbits around our planet. It is not a plant, as it does not possess any characteristics of a living organism. While the moon is indeed round, this is not the primary reason for it being classified as a satellite. Lastly, it is not a glowing object, as its illumination is caused by the reflection of sunlight rather than its own light source.

Explanation
Rotation refers to the circular movement of an object around its axis. In the context of the question, the earth rotates on its axis, causing day and night. This rotation takes approximately 24 hours to complete, resulting in the cycle of day and night. Revolution, on the other hand, refers to the earth's movement around the sun, which takes about 365.25 days to complete. Motion and vibration are not specific to the earth's movement on its axis and do not accurately describe this phenomenon.

Explanation
Walking on the moon is not easy due to the absence of gravity. The moon has only about 1/6th the gravity of Earth, which means that our bodies would feel much lighter and it would be difficult to maintain balance and stability while walking. Additionally, the moon's surface is covered in fine dust, making it slippery and challenging to walk on. Therefore, it is not accurate to say that we can walk on the moon easily.

Explanation
A galaxy is a collection of a million stars, along with gas, dust, and other celestial bodies, held together by gravity. Galaxies come in various shapes and sizes and are the building blocks of the universe. They can contain billions or even trillions of stars, along with other celestial objects like planets, asteroids, and comets. The term "galaxy" is commonly used to refer to the Milky Way, the galaxy in which our solar system resides, but there are countless other galaxies in the universe.

Explanation
Transparent objects allow light to pass through them easily, making them see-through. This means that we can clearly see objects on the other side of transparent materials.