EPRI EXAM 3 QUESTIONS WITH CORRECT
ANSWERS!!
What is statics in mechanics?
Statics is the branch of mechanics that deals with bodies at rest or moving at constant speed,
where all forces are in equilibrium, resulting in acceleration (a) = 0 and the sum of forces (F) = 0.
What is dynamics in mechanics?
Dynamics is the branch of mechanics that deals with bodies undergoing accelerations, where the
sum of forces is not equal to zero.
What is equilibrium in mechanics?
Equilibrium occurs when the resultant of all forces acting on a body is zero.
What characterizes free vibration in vibrating systems?
Free vibration is characterized by motion resembling a sine wave, harmonic motion, with no
energy inputs, vibrating at its natural frequency, exemplified by the Tacoma Narrows Bridge.
What defines forced vibration in vibrating systems?
Forced vibration occurs when a system vibrates at the input frequency after reaching a steady
state, with the natural frequency affecting only the transient state, typically seen in rotating
equipment.
What is undamped vibration?
Undamped vibration refers to a system with no components capable of dissipating energy,
allowing it to continue oscillating indefinitely, though there are no real-world examples.
What is damped free vibration?
Damped free vibration describes an object that dissipates energy in a spring-mass system,
transforming mechanical energy into thermal energy, as seen in suspension systems.
What are centrifugal pumps and how do they operate?
, Centrifugal pumps use rotary motion to impart kinetic energy to liquid, transforming kinetic
energy into flow and pressure, with flow controlled by varying system discharge resistance by a
control valve or varying operating speed.
What are positive displacement pumps and how do they operate?
Positive displacement pumps involve rotary or reciprocating motion, transferring a specific
quantity of fluid per input shaft revolution or plunger stroke, with flow control achieved by
changing speed, stroke length, or using a bypass valve. Found in make-up flow, chemical and
volume control and hydrostatic pressure tests
What is the operational characteristic of positive displacement pumps?
Positive displacement pumps produce the same flow at any given speed regardless of discharge
pressure, making them known as constant flow machines.
What are the risks of operating positive displacement pumps with blocked discharge?
Operating positive displacement pumps with a blocked or restricted discharge is dangerous and
can lead to equipment failure.
What are the types of reciprocating pumps and their applications?
Reciprocating pumps, including piston, plunger, and diaphragm types, are most useful in high
pressure, low flow environments due to their high head capacity.
What is the difference between single acting and double acting reciprocating pumps?
Single acting pumps discharge liquid only on the forward stroke, while double acting pumps
discharge liquid on both the forward and return strokes.
What is the significance of piping in reciprocating pumps?
Piping is crucial in reciprocating pumps as acceleration head and friction loss must be
considered; dampeners or accumulators may be used to mitigate pulsating flow.
What are rotary pumps and their operational principles?
Rotary pumps are positive displacement pumps that consist of chambers containing gears, cams,
screws, or vanes, operated by the relative rotation of the drive shaft or casing.
ANSWERS!!
What is statics in mechanics?
Statics is the branch of mechanics that deals with bodies at rest or moving at constant speed,
where all forces are in equilibrium, resulting in acceleration (a) = 0 and the sum of forces (F) = 0.
What is dynamics in mechanics?
Dynamics is the branch of mechanics that deals with bodies undergoing accelerations, where the
sum of forces is not equal to zero.
What is equilibrium in mechanics?
Equilibrium occurs when the resultant of all forces acting on a body is zero.
What characterizes free vibration in vibrating systems?
Free vibration is characterized by motion resembling a sine wave, harmonic motion, with no
energy inputs, vibrating at its natural frequency, exemplified by the Tacoma Narrows Bridge.
What defines forced vibration in vibrating systems?
Forced vibration occurs when a system vibrates at the input frequency after reaching a steady
state, with the natural frequency affecting only the transient state, typically seen in rotating
equipment.
What is undamped vibration?
Undamped vibration refers to a system with no components capable of dissipating energy,
allowing it to continue oscillating indefinitely, though there are no real-world examples.
What is damped free vibration?
Damped free vibration describes an object that dissipates energy in a spring-mass system,
transforming mechanical energy into thermal energy, as seen in suspension systems.
What are centrifugal pumps and how do they operate?
, Centrifugal pumps use rotary motion to impart kinetic energy to liquid, transforming kinetic
energy into flow and pressure, with flow controlled by varying system discharge resistance by a
control valve or varying operating speed.
What are positive displacement pumps and how do they operate?
Positive displacement pumps involve rotary or reciprocating motion, transferring a specific
quantity of fluid per input shaft revolution or plunger stroke, with flow control achieved by
changing speed, stroke length, or using a bypass valve. Found in make-up flow, chemical and
volume control and hydrostatic pressure tests
What is the operational characteristic of positive displacement pumps?
Positive displacement pumps produce the same flow at any given speed regardless of discharge
pressure, making them known as constant flow machines.
What are the risks of operating positive displacement pumps with blocked discharge?
Operating positive displacement pumps with a blocked or restricted discharge is dangerous and
can lead to equipment failure.
What are the types of reciprocating pumps and their applications?
Reciprocating pumps, including piston, plunger, and diaphragm types, are most useful in high
pressure, low flow environments due to their high head capacity.
What is the difference between single acting and double acting reciprocating pumps?
Single acting pumps discharge liquid only on the forward stroke, while double acting pumps
discharge liquid on both the forward and return strokes.
What is the significance of piping in reciprocating pumps?
Piping is crucial in reciprocating pumps as acceleration head and friction loss must be
considered; dampeners or accumulators may be used to mitigate pulsating flow.
What are rotary pumps and their operational principles?
Rotary pumps are positive displacement pumps that consist of chambers containing gears, cams,
screws, or vanes, operated by the relative rotation of the drive shaft or casing.
