# For noise measurement, formula for sound pressure level (SPL) is 20logP/Pref. What will be the resultant noise in dB if P is 0.0002 u bar

1.  0

2.  60

3.  90

4.  100

4

0

Explanation :
No Explanation available for this question

# Consider the following statements: 1. Particulates have irregular shapes. 2. Size can be determined by an equivalent aerodynamic diameter by comparing with a perfect sphere. 3. Particulates larger than 10 are said to settle relatively quickly since their settling velocity is not less than 10 cm/min. 4. The particles roughly the size of bacteria have aerodynamic diameter of 0.1um to 10um. Which of these statements are correct?

1.  1, 2, 3 & 4

2.  1 & 3 only

3.  1, 2 & 4 only

4.  2, 3 & 4 only

4

1, 2 & 4 only

Explanation :
No Explanation available for this question

# Which of the following factors contribute to formation of photochemical smog 1. Stable atmosphere 2. NOx 3. Solar insolation 4. CO

1.  1, 2, 3, & 4

2.  2, 3 & 4 only

3.  1 & 4 only

4.  1, 2 and 3 only

4

1, 2, 3, & 4

Explanation :
No Explanation available for this question

# It takes 0.4hrs to drive from the garage to the head of the route, 0.4hrs to drive between the route head and disposal site and 0.25hrs to return from the disposal site. It takes 0.2hrs to offload a truck at the disposal site. The crew is permitted two 15-minute breaks and a further 30 minutes for miscellaneous delays. It two runs are made to the deposit site each day, how much time is left in an 8-hr nominal duty duration for refuse collection before starting to return to garage from disposal site Take loading time as 30 minutes.

1.  4.15hrs

2.  4.25hrs

3.  4.75hrs

4.  4.85hrs

4

4.15hrs

Explanation :
No Explanation available for this question

# Consider the following statements: The time of BOD assimilation in a stream can be affected by 1. Ratio of stream depth to flow width. 2. Stream BOD value 3. BOD rate constant. Which of these statements are correct

1.  1, 2 & 3

2.  1 & 2 only

3.  2 & 3 only

4.  1 & 3 only

4

1, 2 & 3

Explanation :
No Explanation available for this question

# The most common constituents of alkalinity in natural water are measured by titrating the water sample with 0.02N H2SO4 using:

1.  Eriochrome Black T and Ferroin indicators

2.  Ferroin and Phenolphthalein indicators

3.  Phenolphthalein and Methyl Orange indicators

4.  Methyl Orange and Ericochrome Black T indicators

4

Phenolphthalein and Methyl Orange indicators

Explanation :
No Explanation available for this question

# A sample of sewage is estimated to have a 5 days 200C BOD of 250 mg/l. If the test temperature be 300 C, in how many days will the same value of BOD be obtained

1.  1.5 days

2.  2.5 days

3.  3.3 days

4.  7.5 days

4

3.3 days

Explanation :
No Explanation available for this question

# A sewer has a diameter of 300 mm and slop of 1 in 400. While running full it has a mean velocity of 0.7 m/s. If both the diameter and slope are doubled (to respectively be 600 mm and 1 in 200), what will be the changed mean velocity when running half-full Use Manning’s formula.

1.  1.59 m/s

2.  2.80 m/s

3.  0.90 m/s

4.  1.00 m/s

4

1.59 m/s

Explanation :
No Explanation available for this question

# Statement (I): In a flownet, each field must be a (curvilinear) square. Statement (II): Each flow channel in a flownet has the same rate of flow.

1.  Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

2.  Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

3.  Statement (I) is true but Statement (II) is false

4.  Statement (I) is false but Statement (II) is true

4

Statement (I) is false but Statement (II) is true

Explanation :
No Explanation available for this question

# Statement (I): Boundary layer theory is applicable only in the vicinity of the leading edge of a flat plate. Statement (II): Boundary layer theory is based on the assumption that its thickness is small when compared to other linear dimensions in the flow.

1.  Both Statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I)

2.  Both Statement (I) and Statement (II) are individually true but Statement (II) is not the correct explanation of Statement (I)

3.  Statement (I) is true but Statement (II) is false

4.  Statement (I) is false but Statement (II) is true

4