Question

Krishna Raja Sagar Reservoir is located on _____________.
A. River Krishna
B. River Kaveri
C. River Mahanadi
D. River Periyar

Answer 1

Hint: Krishna Raja Sagara, also popularly known as KRS, is a lake and the dam that generates it. They are close to the clearing of Krishnarajasagara in the Indian State of Karnataka. One of the designers of the dam was Chief Engineer of Mysore M. Visvesvaraya. There is a decorative garden, Brindavan Gardens, devoted to the dam.

Complete step-by-step solution:
In place of tubes that stop overtopping of dams, Visvesvaraya engaged 48 mechanical gates that open and close at the rise and fall of water in the reservoir, in six sets, with eight in each. Each gate contains a ledge, beam, and side grooves, and plates, balance weight, float, chains, and pulleys, and inlet, and outlet pipes. The gates are fabricated of cast iron and were mass-produced at the Visvesvaraya Iron and Steel Plant in Bhadravati. The 8 sets of gates are linked by means of chains and pulleys to a dead weight, which in turn is linked to a float, making up the 'balance weight' simultaneously, working inside stonework well, both on the back of the dam. The deadweight and float are positioned one behind the other so as to have 4 gates on the individual side of it. When all the 8 gates close the sluice, the balance weight moves to the top of its shift and float to the bottom of the well. The well has a fjord pipe 1 ft ($0.30$ m) in diameter from the reservoir that let water in when the reservoir touches maximum acceptable level instigating the float to rise, the balance weight to fall pulling the gates up letting emancipation of water. In the same machinery, the well gets voided through an exit pipe when the water level in the reservoir falls.

Thus, option (B) is correct.

Note: Foundation Stone to the dam was placed on November 11, 1911. The dam was constructed amidst river Kaveri in 1924. It is the chief supply of water for the districts of Mysore. The water is sourced for irrigation in Mysore and Mandya, and it is the main source of drinking water for all of Mysore, Mandya, and almost the entire of Bengaluru city, the capital of Karnataka. The water freed from this dam streams into the state of Tamil Nadu and is stowed in Mettur dam in the Salem district.