Consider the following statements about a hydraulic ram : 1. Hydraulic ram does not need external power. 2. It works on the fundamental principle of water hammer. 3. The efficiency of a hydraulic ram is only of the order of 8 to 10%. 4. It can be termed as a low, intermittent discharge low-head pumping installation. Which of these statements are correct ?
Which of the following are the purposes of a groyne as a river training structure ? 1. It contracts a river channel to improve its depth. 2. It protects the river bank. 3. It does not allow silt to deposit in the vicinity. 4. It trains the flow along a certain course. Select the correct answer using the code given below :