PhysicsMarichi · UPSC
Dabaav ki Physics: Hydrostatics, Vayumandaliya Dabaav aur Prelims ke Prayog
Kabhi socha hai ki Ladakh jaisi oonchai par daal pakaana mushkil kyun hai, aur pressure cooker wahan bhi kaam kyun aata hai? UPSC yahi 'roz ki physics' poochhta hai — ek hi niyam se paanch sawaal.
Socho pehle… phir dekho jawab
Ek hi jad: dabaav. Oonchai badhi, phir hawa ka dabaav ghata, phir paani ka kvathanank (boiling point) ghata, isliye daal kam taapmaan par ubalti hai aur der se pakti hai. Cooker andar dabaav badha kar kvathanank wapas upar le jaata hai.
Core: P = F/A (Pa). Liquid mein P = P₀ + ρgh; dabaav gehrai, density aur g par tika, shape par nahi (hydrostatic paradox). Pascal: band liquid mein dabaav har jagah bina ghate — hydraulic lift, brake, press. Vayumandaliya dabaav samudra-tal par ≈ 1.01 × 10⁵ Pa ≈ 760 mm Hg ≈ 10.3 m paani; oonchai ke saath ghatta hai.
Prelims prayog: (1) Pressure cooker — dabaav badha, kvathanank badha, khaana jaldi pakta hai. (2) Oonchai par kvathanank kam, aur hawa patli hone se har saans mein oxygen kam milti hai. (3) Suction pump ki seema ~10 m (hawa ka dabaav hi dhakelta hai). (4) Baandh neeche moti — ρgh gehrai ke saath badhta hai. (5) Barometer — tez girta dabaav aksar toofan ka sanket.
Gehra samudra: har ~10 m par ~1 atm; 6,000 m par ~600 atm. Isliye Deep Ocean Mission ki Matsya-6000 (NIOT, MoES) mein teen logon ke liye 80 mm titanium alloy gola hai — gehre samudra ke sansaadhan aur jaiv-vividhata ki khoj ke liye.
Prelims traps: (a) Liquid dabaav bartan ki shape ya kul paani par nahi tika. (b) Hydraulic lift energy nahi badhata — bal badhata hai, doori ghatati hai. (c) Oonchai par paani 'jaldi ubalta' hai par khaana der se pakta hai, kyunki ubalne ka taapmaan kam hai. (d) Gauge pressure = absolute − vayumandaliya.
Humne kya kiya :- Ek niyam (dabaav) ko cooker, oonchai, pump, baandh aur gehre samudra ke paanch prayogon se joda.
Isse kya hua :- Prelims ke 'applied physics' sawaal ab rattne ki jagah ek kadi se hal hote hain: gehrai ya oonchai, phir dabaav, phir asar.
Ghar pe try karo
15 minute: ek page par 'Dabaav ki kadi' banao — beech mein P = P₀ + ρgh, chaaron taraf paanch prayog (cooker, oonchai, pump, baandh, Matsya-6000). Har ek ke saath ek Prelims statement likho jo sahi lage par galat ho (trap). Phir apne dost se hal karwao.
Wow!
Samudra-tal par aapke sar ke upar hawa ka bojh har square metre par lagbhag das tonne ke wazan jitna hai — sharir ke andar ka barabar dabaav use santulit rakhta hai!
3 sawaal
- Oonchai par daal der se kyun pakti hai?
Jawab dekho
Kam vayumandaliya dabaav se paani ka kvathanank ghat jaata hai. Dabaav kam to kvathanank kam; paani kam taapmaan par ubalta hai, isliye khaana der se pakta hai.
- Hydraulic lift ke baare mein sahi kya hai?
Jawab dekho
Bal badhata hai par bada piston kam doori chalta hai. F₁d₁ = F₂d₂: bal mein faayda, doori mein keemat; energy nahi badhti.
- Matsya-6000 kitne logon ko kitni gehrai tak le jaane ke liye bani hai?
Jawab dekho
Teen log, 6,000 m. PIB/MoES: NIOT ki Matsya-6000 teen logon ko 6,000 m tak le jaane ke liye bani, 80 mm titanium alloy gole ke saath.
NCERT se jodo: GS3 — Science & Technology (everyday physics, Deep Ocean Mission); NCERT Class 8, 9 aur 11 ke force, pressure aur fluids ke vichar