Noise & Radiation — Set 2
Environment · ध्वनि और विकिरण · Questions 11–20 of 40
Which of the following is the most penetrating type of nuclear radiation?
Correct Answer: C. Gamma rays
Gamma rays are high-energy photons that can pass through most materials, including the human body. They require thick layers of lead or concrete to be effectively blocked. Alpha particles, by contrast, can be stopped by a simple sheet of paper.
Low-frequency sound waves that are below the range of human hearing are known as?
Correct Answer: A. Infrasound
Infrasound consists of waves with frequencies below 20 Hz, which is the lower limit of human audibility. Sources include natural events like earthquakes and heavy industrial machinery. Even if unheard, infrasound can cause dizziness and nausea in humans.
In the context of radiation protection, the acronym 'ALARA' stands for?
Correct Answer: A. As Low As Reasonably Achievable
The correct answer is 'As Low As Reasonably Achievable'. ALARA is a safety principle used to minimize radiation doses by using every reasonable effort. It focuses on three key factors: time, distance, and shielding. This approach ensures that exposure is kept well below regulatory limits.
Which international organization provides guidelines and standards for radiation protection?
Correct Answer: D. ICRP
The International Commission on Radiological Protection (ICRP) is an independent body that develops recommendations for radiation safety. Its guidelines are used by governments worldwide to frame their national regulations. It focuses on the harmful effects of ionizing radiation on the human body.
What is the permissible noise limit for 'Industrial Areas' during the nighttime in India?
Correct Answer: A. 70 dB
In India, industrial zones have a nighttime noise limit of 70 dB to allow for essential heavy machinery operations. Nighttime is officially calculated from 10 PM to 6 AM. These limits are higher than those for commercial or residential zones.
Which biological effect of radiation involves damage to DNA that can lead to cancer decades later?
Correct Answer: C. Stochastic effects
Stochastic effects are those where the probability of occurrence increases with the dose, but the severity does not. Cancer and genetic mutations are typical examples of these long-term delayed risks. There is generally no safe threshold dose for these types of effects.
The unwanted ringing or buzzing sensation in the ears caused by loud noise exposure is called?
Correct Answer: D. Tinnitus
Tinnitus is often a symptom of underlying hearing loss or circulatory system disorders. It occurs when the auditory nerves are damaged and send false signals to the brain. It is a very common condition among people working in high-noise environments.
Which element is primarily used in the construction of protective aprons for workers in X-ray rooms?
Correct Answer: A. Lead
Lead has a very high atomic number and density, making it excellent for absorbing X-ray radiation. Lead aprons protect vital organs from scattered radiation during medical procedures. It is the most effective and affordable shielding material for low-to-medium energy rays.
Which environmental factor can significantly increase the distance noise travels at night?
Correct Answer: C. Temperature inversion
Temperature inversion occurs when cold air is trapped near the ground by a warmer layer above. This causes sound waves to refract or bend back toward the earth instead of dissipating into the sky. Consequently, noise from distant roads or factories sounds much louder.
What is the primary health impact of 'Electromagnetic Radiation' from mobile towers according to standard safety norms?
Correct Answer: D. Thermal (Heating) effect
Non-ionizing radiofrequency radiation primarily causes the heating of biological tissues. Most regulatory bodies set emission limits to ensure this heating remains within safe levels. Whether long-term non-thermal effects exist is still a subject of ongoing research.