Science · X-Factor Notes
MECHANICS revision notes for UPPCS Prelims.
13 revision facts
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Mechanics | Area of science concerned with the behaviour of physical bodies when subjected to force or displacements and the subsequent effects on their environment. | |
| Mass | Represents the amount of matter in an object; it is constant at every place. | |
| Weight | The force exerted in a body by gravity. | |
| Vector Quantity | A physical quantity that has both magnitude and direction. Examples include velocity, displacement, acceleration, force, and momentum. | I.A.S. (Pre) 1997 |
| Scalar Quantity | A physical quantity that has only magnitude. Examples include distance, volume, speed, pressure, energy, work, and density. | |
| Simple Machine (Function) | Helps a person in performing the same amount of work with lesser force. Examples: pulley, lever, wheel, screw. | I.A.S. (Pre) 1996 |
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Energy Conservation | Energy can neither be created nor destroyed. | I.A.S. (Pre) 1996 |
| Momentum / Velocity Ratio | The ratio of momentum (p) and velocity (v) of a body represents its mass (m), derived from the formula p = mv. | |
| Frictionless Surface Propulsion | A man standing on a frictionless surface can propel himself by whistling. This relates to the principle that if no external force acts on a system, its momentum cannot change (Conservation of Momentum). |
| Concept | What to remember | Asked in UPPCS |
|---|---|---|
| Light Energy to Electrical Energy | Achieved using a solar cell. | UPPCS (Mains) 2002 |
| Electrical Energy to Sound Energy | Achieved using a loudspeaker. | UPPCS (Mains) 2002 |
| Mass Energy to Heat Energy | Achieved using a nuclear reactor. | UPPCS (Mains) 2002 |
| Chemical Energy to Heat and Light Energy | Achieved through fuel combustion. | UPPCS (Mains) 2002 |
