Test: Science And Technology - 1 - Class 5 MCQ

Volatile Memory in MS-Word:
RAM (Random Access Memory) is the volatile memory that stores all the data of the MS-Word application that is currently running on the computer. Here is a detailed explanation:
RAM (Random Access Memory):
- RAM is a type of computer memory that is used to store data that the computer is actively using.
- It is considered volatile because its contents are lost when the computer is turned off or restarted.
- RAM provides a fast and temporary storage space for the data and instructions that are currently being processed by the computer.
- When you open MS-Word application on your computer, it loads into the RAM, allowing you to work on your documents smoothly.
- RAM allows the computer to quickly access and retrieve data, which improves the performance of the MS-Word application.
Other Options:
- Hard Disk: Hard disk is a non-volatile storage device used to store data permanently. It is not directly involved in storing the data of the running MS-Word application.
- ROM (Read-Only Memory): ROM is a non-volatile memory that stores permanent instructions for the computer. It is not directly involved in storing the data of the running MS-Word application.
- Flash Drive: Flash drive is an external storage device that can be used to store data, but it is not the primary memory used by the MS-Word application while it is running.
Therefore, the correct answer is C: RAM.

Explanation:
To form a shadow, the following components are required:
1. Source of light: A shadow is formed when light rays from a source hit an object and are blocked, causing a dark region to appear behind the object.
2. Opaque object: An opaque object is necessary to block the path of light, preventing it from reaching the screen or any other surface.
3. Screen or surface: The screen or surface is where the shadow is formed. It is the area where the light is blocked by the opaque object, resulting in a dark region.
However, a lens is not required for the formation of a shadow. A lens is a transparent object that can refract or bend light. Since a shadow is formed by blocking light, the presence of a lens would not have any effect on the formation of a shadow.
Therefore, the correct answer is D: Lens.

Facts about asteroids:
A: Asteroids do not revolve around the Sun the way planets do.
- Asteroids do orbit the Sun, but their orbits are different from those of planets.
- They have more elliptical and tilted orbits compared to the relatively circular and aligned orbits of planets.
B: The asteroid belt is between Venus and Jupiter.
- This statement is incorrect. The asteroid belt is located between the orbits of Mars and Jupiter.
- It is a region in the Solar System where numerous asteroids are found.
C: Asteroids are planet-like objects, but smaller and often irregularly shaped.
- This statement is correct.
- Asteroids are rocky objects that are remnants from the early Solar System.
- They are smaller than planets and can vary in size from a few meters to hundreds of kilometers.
- Most asteroids have irregular shapes, although some larger ones may have a more rounded appearance.
D: Asteroids cannot be classified into groups.
- This statement is incorrect.
- Asteroids can be classified into different groups based on their composition, location, and characteristics.
- For example, there are carbonaceous (C-type), silicate (S-type), and metallic (M-type) asteroids.
- Additionally, some asteroids are classified as Near-Earth asteroids (NEAs) if their orbits bring them relatively close to Earth.
Therefore, the correct fact about asteroids is option C: Asteroids are planet-like objects, but smaller and often irregularly shaped.

Physical Change:
A physical change is a change in which the substance undergoes a transformation that does not result in the formation of a new substance. In this type of change, the substance can be reversed back to its original form.
Examples of Physical Changes:
D: Melting of ice: When ice is heated, it changes from a solid state to a liquid state. However, the process of melting can be reversed by cooling the liquid water, which will result in the formation of ice again. Therefore, the melting of ice is a physical change.
Explanation:
- The burning of paper (A) is a chemical change because it results in the formation of new substances like ash, smoke, and gases.
- Bursting of crackers (B) is also a chemical change as it involves a rapid reaction resulting in the formation of new substances, such as gases, light, and sound.
- Cooking of food (C) is a chemical change as it involves the application of heat and the transformation of raw ingredients into cooked food with changed properties.
Therefore, the correct answer is D: Melting of ice.

Not a Satellite of Earth:
- Phobos: Phobos is not a satellite of Earth. It is actually a moon of Mars, one of the two moons that orbit the red planet.
Other Satellites of Earth:
- GSAT-7: GSAT-7 is an artificial satellite launched by the Indian Space Research Organisation (ISRO). It is primarily used for communication purposes by the Indian Navy.
- International Space Station (ISS): The ISS is a habitable artificial satellite that orbits around the Earth. It is a joint project between NASA, Roscosmos, ESA, JAXA, and CSA, and serves as a research laboratory and living space for astronauts from various countries.
- Moon: The Moon is Earth's only natural satellite. It is the fifth-largest moon in the Solar System and plays a crucial role in stabilizing Earth's rotation and tides.

Number of Oceans on Earth:
- The question asks how many oceans are there on Earth, based on the fact that almost 71% of the Earth's surface is covered by oceans.
- The options provided are A: 3, B: 4, C: 5, and D: 6.
- To determine the correct answer, we need to identify the major oceans on Earth.
Major Oceans on Earth:
1. Pacific Ocean: The Pacific Ocean is the largest and deepest ocean on Earth. It covers an area of approximately 63 million square miles, which is more than the combined area of all the other oceans.
2. Atlantic Ocean: The Atlantic Ocean is the second-largest ocean and separates the Americas from Europe and Africa. It covers an area of about 41 million square miles.
3. Indian Ocean: The Indian Ocean is the third-largest ocean and is located between Africa, Asia, and Australia. It covers an area of approximately 27 million square miles.
4. Southern Ocean: The Southern Ocean, also known as the Antarctic Ocean, surrounds Antarctica. It is the fourth-largest ocean and covers an area of about 7.8 million square miles.
Determining the Number of Oceans:
- Based on the major oceans listed above, we can see that there are four distinct oceans on Earth.
- Therefore, the correct answer is B: 4.
Conclusion:
- There are four major oceans on Earth: the Pacific Ocean, Atlantic Ocean, Indian Ocean, and Southern Ocean.
- The answer to the given question is B: 4.

The instrument used in submarines to observe activity above the water surface while the submarine is submerged is called a periscope. Here is a detailed explanation of why the correct answer is C: Periscope.
Periscope:
- A periscope is an optical device that uses mirrors or prisms to reflect and redirect light, allowing users to see objects that are not in their direct line of sight.
- It consists of a long tube with a system of mirrors or prisms that reflect the light entering through one end and redirect it towards the viewer's eye at the other end.
- Periscopes are commonly used in submarines to provide a view of the surrounding environment without having to surface.
- The periscope is usually mounted on the top of the submarine's hull and can be raised or lowered as needed.
- By using a periscope, submarine operators can observe the activities happening above the water surface, such as the positions of other ships, landmarks, or potential threats, while remaining hidden underwater.
Incorrect options:
A: Binoculars - Binoculars are handheld optical devices with two separate lenses that provide a magnified view of distant objects. They are not specifically designed for use in submarines.
B: Telescope - Telescopes are optical devices used to observe distant objects in space or on Earth. They are not typically used in submarines for observing activity above the water surface.
D: Kaleidoscope - A kaleidoscope is a toy or optical instrument that creates colorful and symmetrical patterns by reflecting light off multiple mirrors. It is not used in submarines for observing activity above the water surface.
Therefore, the correct instrument used in submarines to observe activity above the water surface while submerged is a periscope.