Critical Yield of Open Well and Recuperation Test

Q. Specific capacity of a well is the

1. Volume of water that can be extracted by the force of gravity from a unit volume of aquifer
2. discharge per unit drawdown of the well
3. drawdown per unit discharge of the well
4. rate of flow through a unit width and entire thickness of aquifer

Q. The discharge per unit drawdown at the well is known as

1. Specific yield
2. Specific storage
3. Specific retention
4. Specific capacity

Q. Discharge per unit drawdown at an open well is known as

1. specific storage
2. specific capacity
3. specific yield
4. specific retention

Q. The performance of a well is measured by its

1. Specific capacity
2. Specific yield
3. Storage coefficient
4. Permeability coefficient

Q. The yield of a well depends upon

1. permeability of soil
2. area of aquifer opening into the wells
3. actual flow velocity
4. all of the above

Q. Match List-I with List-II and select the correct answer using the codes given below the lists:
List - I
A. Specified yield
B. Specific capacity
C. Specific retention
D. Specific storage

List-II
1. Volume of water retained per unit volume of aquifer
2. Volume of water drained by gravity per unit volume of aquifer
3. Difference of porosity and specific storage
4. Well yield per unit drawdown
5. Volume of water released from unit volume of aquifer for unit decline in piezometric head

1. A-2, B-4, C-1, D-5
2. A-4, B-2, C-3, D- 5
3. A-2, B-5, C-1, D-4
4. A-4, B-2, C-3, D-1

Q. Match List - I (Well hydraulics parameters) with List - II (Definition) and select the correct answer using the codes given below the lists:
List-I
A. Specific yield
B. Safe yield
C. Specific capacity
D. Field capacity

List-II
1. Discharge per unit drawdown of well
2. Same as specific retention
3. Measure of water that can be removed by pumping
4. Limit of withdrawal from well without depletion of the aquifer
5. Water-bearing capacity of aquifer

1. A-4, B-3, C-2, D-5
2. A-3, B-4, C-1, D-2
3. A-4, B-3, C-1, D-2
4. A-3, B-4, C-2, D-5

Q. A 5 m diameter open well has a discharge of 40 cumecs under a depression head of 3 m. What will be the discharge (in cumecs) from a 8 m diameter open well in the same aquifer under a depression head of 2 m?

1. 26.67
2. 40
3. 51.26
4. 68.27