EMC1 S5 Recap

Which of the following is NOT one of the basic noise control techniques mentioned in the presentation?

• Noise reduction at source
• Attenuation in transmission
• Protection of the receiver
• Increasing ambient noise levels

What is a benefit of replacing diesel/petrol motors with electric motors?

• Increased power output
• Noise reduction
• Lower initial cost
• Improved fuel efficiency

Which of the following is NOT a characteristic of effective noise isolation enclosures?

• Having a heavy, noise-reflecting outer skin
• Having a noise-absorbent lining
• Being mounted to transmit noise and vibrations
• Being airtight

What is the primary difference between noise absorption and noise insulation?

• Absorption uses porous materials, insulation uses barriers
• Absorption increases noise, insulation decreases it
• Absorption works indoors, insulation works outdoors
• Absorption is for high frequencies, insulation is for low frequencies

According to the presentation, approximately how much noise reduction can screens placed near a noise source achieve?

• 1 to 3 dB
• 5 to 10 dB
• 15 to 20 dB
• 25 to 30 dB

Which of the following is NOT mentioned as a management control for noise?

• Control of working hours
• Controlling the use of radios
• Mandating use of noise-cancelling headphones
• Vehicle routes

What does the term 'potable' mean in relation to water?

• Fit for drinking
• Contaminated
• Filtered
• Boiled

Which of the following is NOT listed as a characteristic of safe drinking water?

• Free from pathogenic bacteria
• Low turbidity
• High mineral content
• No unpleasant taste or smell

What is a potential consequence of over-abstraction from aquifers near coastal areas?

• Increased biodiversity
• Salt water intrusion
• Higher water quality
• Improved agricultural yields

Which of the following is NOT mentioned as an impact of water pollution on wildlife?

• Physical impacts on lake and river bottoms
• Oxygen stress in aquatic environments
• Increased species diversity
• Toxicity from chemical spills