engineering recuitment BHEL Engineer Trainee Mock Test 2025 Environmental Engineering Air and Noise Pollution
What will be the resultant decibel level when there are 4 sources making noise of equal levels?
1
Decibel level will increase by 4 decibels.
2
Decibel level will increase by 6 decibels.
3
Decibel levels will remain the same.
4
Decibel level will increase by 8 decibels.