This page covers RRB Group D Physics — Everyday Concepts with complete concept notes, 3 graded practice MCQs, key points and exam-specific tips. Free to study.
Pressure = Force ÷ Area. When you press a drawing pin into a board, the sharp point creates high pressure because the same force is concentrated on a tiny area. This is why pins pierce easily but your finger pressing with the same force cannot
💡Key Properties
Pressure is directly proportional to force and inversely proportional to area. Double the force, double the pressure. Double the area, halve the pressure. Pressure acts in all directions in fluids (Pascal's Law).
At any point in a stationary fluid, pressure is the same in all directions.
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Formula Block
Memorise — at least one formula appears in every paper
Pressure (P) = Force (F) ÷ Area (A)
Fluid Pressure = Density × g × Height
Atmospheric Pressure = 1.013 × 10^5 Pa = 760 mm Hg
Units: Pascal (Pa), N/m², Bar, Atmosphere, mm Hg
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Exam Patterns
What examiners ask — read before attempting PYQs
SSC asks about atmospheric pressure values, pressure applications (hydraulic systems, barometers), and calculation problems. Questions often involve pressure differences at heights, pressure in liquids, and practical applications like syringes, pumps.
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Shortcuts
Use these to save 30–60 seconds per question
Remember 'FAPA' - Force and Area are in Pressure Always. Increase Force = Increase Pressure. Increase Area = Decrease Pressure.
For fluid pressure, remember 'DGH' - Density × Gravity × Height.
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Worked Example
Solve this step-by-step before moving on
1
Step 1
Identify given values - Force = 200 N, Area = 4 m²
2
Step 2
Apply formula - Pressure = Force ÷ Area
3
Step 3
Substitute values - Pressure = 200 ÷ 4
4
Step 4
Calculate - Pressure = 50 N/m² or 50 Pa
Another Example: If the same 200 N force acts on 2 m² area instead:
Pressure = 200 ÷ 2 = 100 Pa
Notice: Half the area means double the pressure.
Shortcut for Unit Conversion: 1 Bar = 10^5 Pa. For quick conversion, Bar to Pa - add 5 zeros. Pa to Bar - remove 5 zeros.
Common Mistakes: Students often confuse force with pressure. Remember - force is push or pull, pressure is force per unit area. Another mistake is forgetting that liquid pressure depends on depth (height of liquid column), not the total volume. A thin tube and wide tank at same depth have equal pressure at bottom.
Practical Applications tested: Hydraulic brakes work on Pascal's law. Barometers measure atmospheric pressure. Syringes work due to pressure difference. Mountain climbers face low pressure at heights. Deep sea divers face high pressure underwater.
Test Physics — Everyday Concepts under exam conditions
Which of the following is the SI unit of electric current?
Practice 2medium
A ball is thrown vertically upward with an initial velocity of 20 m/s. Assuming g = 10 m/s², what is the maximum height reached by the ball above the point of projection?
Practice 3hard
A person standing on the ground observes that the angle of elevation to the top of a building is 30°. When the person moves 20 meters closer to the building along the same line, the angle of elevation becomes 60°. What is the height of the building?
60-Second Revision — Physics — Everyday Concepts
Formula: Pressure = Force ÷ Area, units Pascal or N/m²
Remember: 1 atm = 1.013 × 10^5 Pa = 760 mm Hg
Liquid pressure depends only on depth, not container shape or volume
Pascal's Law: Pressure transmits equally in all directions in fluids
Applications: Hydraulic brakes, barometers, syringes all use pressure principles
Trap: Don't confuse force with pressure - pressure is force per unit area
Quick conversion: 1 Bar = 10^5 Pa (add/remove 5 zeros)