Vodafone Idea Interview Questions and Answers

Negative slip in reciprocating pump occurs when the pump runs faster than the synchronous speed of the motor.

• Negative slip occurs when the pump runs faster than the synchronous speed of the motor.

• This can happen if the pump is not properly matched to the motor or if there is a mechanical issue causing the pump to run faster.

• Negative slip can lead to decreased efficiency and potential damage to the pump.

Pump discharge flow rate can be calculated using the formula Q = A * V, where Q is the flow rate, A is the cross-sectional area of the pipe, and V is the velocity of the fluid.

• Calculate the cross-sectional area of the pipe using the formula A = π * r^2, where r is the radius of the pipe.

• Determine the velocity of the fluid by measuring the speed at which the fluid is flowing through the pipe.

• Multiply the cross-sectional area of the pipe by the velocity of the fluid to calculat...read more

The velocity of flow at the inlet of a Kaplan turbine is typically high due to the design of the turbine blades.

• The velocity of flow at the inlet of a Kaplan turbine is usually between 3 to 10 m/s.

• The high velocity at the inlet helps in maximizing the energy extraction efficiency of the turbine.

• The design of the Kaplan turbine blades allows for efficient energy conversion from the flowing water to rotational motion.

Kaplan turbines are used for low head because they are designed to operate efficiently in low head conditions.

• Kaplan turbines have adjustable blades that allow for optimal performance in low head situations

• They have a higher specific speed compared to other turbine types, making them suitable for low head applications

• Examples of low head applications include run-of-river hydroelectric plants and irrigation systems

Theoretical discharge pump formula calculates the flow rate of a pump based on various parameters.

• Theoretical discharge pump formula: Q = A * V

• Q = flow rate (volume per unit time)

• A = cross-sectional area of the pipe or pump outlet

• V = velocity of the fluid

• Example: If A = 0.5 m^2 and V = 2 m/s, then Q = 1 m^3/s

w q m stands for weight flow rate in fluid mechanics.

• w q m is a measure of the mass of fluid passing through a given point per unit time.

• It is calculated by multiplying the mass flow rate by the acceleration due to gravity.

• Common units for weight flow rate include kg/s or lb/s.