Pressure increase with Depth : Pressure in Liquids (Water) | āϤ⧰āϞāϤ āĻāĻžāĻĒ (āĻĒāĻžāύā§)
Pressure in Liquids (Water) | āϤ⧰āϞāϤ āĻāĻžāĻĒ (āĻĒāĻžāύā§)
Concept Visualization
Statement (āĻŦāĻžāĻā§āϝ)
Water from the lowest hole spurts out with the greatest force because pressure increases with depth. (āϏ⧰ā§āĻŦāύāĻŋāĻŽā§āύ āĻāĻŋāĻĻā§ā§°ā§° āĻĒā§°āĻž āĻĒāĻžāύ⧠āϏ⧰ā§āĻŦāĻžāϧāĻŋāĻ āĻā§ā§°ā§ āĻāϞāĻžāĻ āĻāĻžā§°āĻŖ āĻāĻā§ā§°āϤāĻž āĻŦāĻžāĻĸāĻŧāĻŋāϞ⧠āĻāĻžāĻĒā§ āĻŦāĻžāĻĸāĻŧā§āĨ¤)
Explanation (āĻŦā§āϝāĻžāĻā§āϝāĻž)
- In liquids, pressure depends on depth : āϤ⧰āϞāϤ āĻāĻžāĻĒ āĻāĻā§ā§°āϤāĻžā§° āĻāĻĒā§°āϤ āύāĻŋā§°ā§āĻā§° āĻā§°ā§
- Deeper point → more water above → more weight → more pressure : āϝāĻŋāĻŽāĻžāύ āϤāϞāϞ⧠āϝāĻžāϝāĻŧ → āĻāĻĒā§°āϤ āĻĒāĻžāύā§ā§° āĻĒā§°āĻŋāĻŽāĻžāĻŖ āĻŦā§āĻāĻŋ → āĻāĻāύ āĻŦā§āĻāĻŋ → āĻāĻžāĻĒ āĻŦā§āĻāĻŋ
- So, the lowest hole has maximum pressure : āϏā§āϝāĻŧā§ āϤāϞ⧰ āĻāĻŋāĻĻā§ā§°āϤ āϏ⧰ā§āĻŦāĻžāϧāĻŋāĻ āĻāĻžāĻĒ āĻĨāĻžāĻā§
- Hence, water comes out with greatest force : āĻĢāϞāϤ āĻĒāĻžāύ⧠āĻŦā§āĻāĻŋ āĻā§ā§°ā§ āĻāϞāĻžāĻ
Formula (āϏā§āϤā§ā§°) : P=hρg
Where (āϝ’āϤ):
- h = depth (āĻāĻā§ā§°āϤāĻž)
- ρ (rho) = density of liquid (āĻāύāϤā§āĻŦ)
- g = gravity (āĻŽāĻžāϧā§āϝāĻžāĻāϰā§āώāĻŖ)
Key Points (āĻā§āϰā§āϤā§āĻŦāĻĒā§āϰā§āĻŖ āĻāĻĨāĻž)
- Pressure increases with depth : āĻāĻā§ā§°āϤāĻž āĻŦāĻžāĻĸāĻŧāĻŋāϞ⧠āĻāĻžāĻĒ āĻŦāĻžāĻĸāĻŧā§
- Lowest hole → maximum pressure : āϤāϞ⧰ āĻāĻŋāĻĻā§ā§° → āϏ⧰ā§āĻŦāĻžāϧāĻŋāĻ āĻāĻžāĻĒ
- Same liquid → deeper = stronger flow : āĻāĻā§ āϤ⧰āϞ → āĻāĻā§ā§°āϤāĻž āĻŦā§āĻāĻŋ = āĻā§ā§° āĻŦā§āĻāĻŋ
Real-Life Examples (āĻŦāĻžāϏā§āĻ¤ā§ą āĻāĻĻāĻžāĻšā§°āĻŖ)
- Dams are thicker at the bottom : āĻĄā§āĻŽ āϤāϞāĻĢāĻžāϞ⧠āĻĄāĻžāĻ āĻā§°āĻž āĻšāϝāĻŧ
- Divers feel more pressure underwater : āĻĄā§āĻŦāĻžā§°ā§ā§ā§ āϤāϞāϞ⧠āĻ’āϞ⧠āĻāĻžāĻĒ āĻŦā§āĻāĻŋ āĻ āύā§āĻā§ą āĻā§°ā§
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MCQ
1. Liquid pressure depends on — | āϤ⧰āϞ⧰ āĻāĻžāĻĒ āĻāĻŋāĻšā§° āĻāĻĒā§°āϤ āύāĻŋā§°ā§āĻā§° āĻā§°ā§ ?
A. Color B. Depth C. Shape D. Temperature
Ans: B. Depth
Explanation: Pressure increases with depth. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻā§ā§°āϤāĻž āĻŦāĻžāĻĸāĻŧāĻŋāϞ⧠āĻāĻžāĻĒ āĻŦāĻžāĻĸāĻŧā§āĨ¤
2. Water from the lowest hole comes out with — | āϤāϞ⧰ āĻāĻŋāĻĻā§ā§°ā§° āĻĒā§°āĻž āĻĒāĻžāύ⧠āĻā§āύā§āĻā§ āĻāϞāĻžāĻ ?
A. Least force B. Same force C. Greatest force D. No force
Ans: C. Greatest force
Explanation: Lowest point has maximum pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āϤāϞ⧰ āĻ
āĻāĻļāϤ āĻāĻžāĻĒ āĻŦā§āĻāĻŋāĨ¤
3. Pressure in a liquid increases with — | āϤ⧰āϞāϤ āĻāĻžāĻĒ āĻŦāĻžāĻĸāĻŧā§ —
A. Height from bottom B. Depth C. Area D. Shape
Ans: B. Depth
Explanation: More depth → more pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻā§ā§°āϤāĻž āĻŦā§āĻāĻŋ → āĻāĻžāĻĒ āĻŦā§āĻāĻŋāĨ¤
4. Which hole will throw water farthest ? | āĻā§āύāĻā§ āĻāĻŋāĻĻā§ā§°ā§ āĻĒāĻžāύ⧠āϏ⧰ā§āĻŦāĻžāϧāĻŋāĻ āĻĻā§ā§°āϞ⧠āϝāĻžāĻŦ ?
A. Top hole B. Middle hole C. Bottom hole D. All same
Ans: C. Bottom hole
Explanation: Bottom hole has highest pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āϤāϞ⧰ āĻāĻŋāĻĻā§ā§°āϤ āĻāĻžāĻĒ āĻŦā§āĻāĻŋāĨ¤
5. The formula of liquid pressure is — | āϤ⧰āϞ āĻāĻžāĻĒā§° āϏā§āϤā§ā§° āĻāĻŋ ?
A. P = F/A B. P = m/v C. P = hρg D. P = mv
Ans: C. P = hρg
Explanation: Pressure depends on depth, density, gravity. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻā§ā§°āϤāĻž, āĻāύāϤā§āĻŦ, āĻŽāĻžāϧā§āϝāĻžāĻāϰā§āώāĻŖā§° āĻāĻĒā§°āϤ āύāĻŋā§°ā§āĻā§° āĻā§°ā§āĨ¤
6. Why are dams thicker at the bottom ? | āĻĄā§āĻŽ āϤāϞāĻĢāĻžāϞ⧠āĻĄāĻžāĻ āĻāĻŋāϝāĻŧ āĻšāϝāĻŧ ?
A. Less pressure B. More pressure C. Less water D. Less gravity
Ans: B. More pressure
Explanation: Pressure is maximum at bottom. āĻŦā§āϝāĻžāĻā§āϝāĻž: āϤāϞāĻĢāĻžāϞ⧠āĻāĻžāĻĒ āĻŦā§āĻāĻŋāĨ¤
7. A diver feels more pressure because — | āĻĄā§āĻŦāĻžā§°ā§ā§ā§ āĻŦā§āĻāĻŋ āĻāĻžāĻĒ āĻ āύā§āĻā§ą āĻā§°ā§ āĻāĻžā§°āĻŖ —
A. Less water B. More depth C. Less gravity D. Less area
Ans: B. More depth
Explanation: Greater depth → higher pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻā§ā§°āϤāĻž āĻŦā§āĻāĻŋ → āĻāĻžāĻĒ āĻŦā§āĻāĻŋāĨ¤
8. At same depth, pressure is — | āĻāĻā§ āĻāĻā§ā§°āϤāĻžāϤ āĻāĻžāĻĒ āĻā§āύā§āĻā§ā§ąāĻž ?
A. Different B. Same C. Zero D. Maximum
Ans: B. Same
Explanation: Same depth → same pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻāĻā§ āĻāĻā§ā§°āϤāĻž → āĻāĻā§ āĻāĻžāĻĒāĨ¤
9. Liquid pressure does NOT depend on — | āϤ⧰āϞ āĻāĻžāĻĒ āĻāĻŋāĻšā§° āĻāĻĒā§°āϤ āύāĻŋā§°ā§āĻā§° āύāĻā§°ā§ ?
A. Depth B. Density C. Shape of container D. Gravity
Ans: C. Shape of container
Explanation: Shape does not affect pressure. āĻŦā§āϝāĻžāĻā§āϝāĻž: āĻĒāĻžāϤā§ā§°ā§° āĻāĻā§āϤāĻŋā§° āĻĒā§ā§°āĻāĻžā§ą āύāĻžāĻĨāĻžāĻā§āĨ¤
10. Unit of liquid pressure is — | āϤ⧰āϞ āĻāĻžāĻĒā§° āĻāĻāĻ āĻāĻŋ ?
A. Newton B. Pascal C. Joule D. Watt
Ans: B. Pascal
Explanation: SI unit is Pascal. āĻŦā§āϝāĻžāĻā§āϝāĻž: SI āĻāĻāĻ āĻĒāĻžāϏā§āĻā§āϞāĨ¤
Revision (āĻĒā§āύ⧰āĻžāϞā§āĻāύāĻž) : Pressure increases with depth (āĻāĻā§ā§°āϤāĻž āĻŦāĻžāĻĸāĻŧāĻŋāϞ⧠āĻāĻžāĻĒ āĻŦāĻžāĻĸāĻŧā§)