Direct Methods of River Gauging

Q. A 35 gm/l solution of tracer was discharged into stream at a constant rate of $12c{m}^3/s$. The background concentration of tracer in stream water was found to be zero. If the discharge of stream is $50m^3/s$ then the equilibrium concentration of the tracer at a downstream section sufficiently far away is____ $\times {10}^{6}gm/l$.

1. 4.8
2. 6.6
3. 7.2
4. 8.4

Q. $A20mg/l$ solution of a fluorescent dye was discharged into a stream at a constant rate of $10c{m}^3/sec.$.The background concentration of the dye in the stream water was found to be zero. At concentration of 5 parts per billion. The discharge will be
[Use constant rate injection method]

1. $0.040m^3/s$
2. $0.038m^3/s$
3. $0.035m^3/s$
4. $0.032m^3/s$

Q. Consider the following statements regarding moving boat method

1. It is suitable for very wide stream

2. The velocity of boat is required for discharge computation

3. Steady flow conditions are preferred

Which of the above statements is/are correct ?

1. 1 only
2. 2 only
3. 3 only
4. 1 and 3