Q3 A) Answer the following questions in brief (Any 2)
1) What is meant by noise pollution?
2) Why is it necessary to maintain the machines?
3) What is a shadow?
4) Write any two practical uses of a magnet.
Answers
Answer:
1.Noise pollution can be defined as any disturbing or unwanted noise that interferes or harms humans or wildlife. Noise pollution has a negative impact on wildlife species by reducing habitat quality, increasing stress levels, and masking other sounds.
2.The importance to service and maintain your machine regularly is to keep it functioning and operating at 100% efficiency. Using, for example, daily inspections can drive the level of response required the engineers.
3.shadow is a dark (real image) area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light.
4.Magnets are used to make a tight seal on the doors to refrigerators and freezers. They power speakers in stereos, earphones, and televisions. Magnets are used to store data in computers, and are important in scanning machines called MRIs (magnetic resonance imagers), which doctors use to look inside people's bodies.
Answer:
1. Noise that harms and/or disturbs human activities or wildlife. This is usually an exposure to high sound volumes.
It basically means noise that can harm you (hearing loss and extreme stress) if you are exposed to it for too long.
4. Magnets are used to hold things closed tightly like your mailbox. Newer mailboxes have magnets to hold the door closed even in very windy/rainy conditions.
Compasses use magnets. A compass uses a magnet to direct its needle to the north pole.
Explanation: