Question 1

Which unit is used to measure the intensity or loudness of sound?

Accepted Answer

Decibel. The decibel (dB) is the standard logarithmic unit used to measure sound intensity. A higher decibel value indicates a louder sound that can potentially cause hearing damage. Generally, sounds above 85 dB are considered harmful over long durations.

Question 2

Which type of radiation has enough energy to remove electrons from atoms or molecules?

Accepted Answer

Ionizing radiation. Ionizing radiation includes high-energy rays like X-rays and Gamma rays that can strip electrons from atoms. This process can cause chemical changes in living cells and damage DNA structures. It is commonly found in nuclear materials and cosmic rays.

Question 3

According to the Noise Pollution (Regulation and Control) Rules, what is the daytime noise limit for a Residential Area?

Accepted Answer

55 dB. The prescribed limit for residential areas during the day is 55 decibels. Daytime is usually defined as the period from 6 AM to 10 PM. Keeping noise within these limits is essential for the psychological well-being of residents.

Question 4

Which radioactive gas is a natural source of radiation often found accumulating in poorly ventilated basements?

Accepted Answer

Radon. Radon is a colorless, odorless gas produced by the natural decay of uranium in soil and rocks. It can leak into buildings through cracks and become a significant health risk when inhaled. It is widely recognized as a major cause of lung cancer globally.

Question 5

What is the threshold frequency for sound to be classified as 'Ultrasound'?

Accepted Answer

Above 20,000 Hz. Ultrasound refers to sound waves with frequencies higher than the upper audible limit of human hearing, which is 20 kHz. While not usually perceived as noise, it is used in medical imaging and industrial cleaning. Many animals like bats and dolphins use these frequencies for navigation.

Noise & Radiation — Set 1