What is Pressure = ?


Pressure : āϚāĻžāĻĒ


Pressure is the force acting per unit area. āϚāĻžāĻĒ āĻšā§ˆāϛ⧇ āĻāĻ•āĻ• āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāϤ āĻĒā§ā§°āϝāĻŧā§‹āĻ— āϕ⧰āĻž āĻŦāϞāĨ¤


Formula / āϏ⧂āĻ¤ā§ā§° : P = F/A


Where / āϝ’āϤ : = Pressure (āϚāĻžāĻĒ), = Force (āĻŦāϞ), = Area (āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ)


SI Unit / SI āĻāĻ•āĻ• : Pascal (Pa) - āĻĒāĻžāĻ¸ā§āĻ•āĻžāϞ (Pa)


Important Point  / āϗ⧁⧰⧁āĻ¤ā§āĻŦāĻĒā§‚āĻ°ā§āĻŖ āĻ•āĻĨāĻž



  • Greater force produces greater pressure. (āĻ…āϧāĻŋāĻ• āĻŦāϞ⧇ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āϕ⧰⧇āĨ¤)

  • Smaller area produces greater pressure. (āĻ•āĻŽ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāϤ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āϏ⧃āĻˇā§āϟāĻŋ āĻšāϝāĻŧāĨ¤)


Examples / āωāĻĻāĻžāĻšā§°āĻŖ



  • Sharp knives cut easily because pressure is high on a small area. (āϧāĻžāϰāĻžāϞ⧋ āϛ⧁⧰⧀āϝāĻŧ⧇ āϏāĻšāĻœā§‡ āĻ•āĻžāĻŸā§‡ āĻ•āĻžā§°āĻŖ āĻ•āĻŽ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāϤ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āĻšāϝāĻŧāĨ¤)

  • High heels exert more pressure on the ground. (High heel-āĻ āĻŽāĻžāϟāĻŋāϤ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āĻĒā§ā§°āϝāĻŧā§‹āĻ— āϕ⧰⧇āĨ¤) 


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Pressure – 2 Marks Questions with Answers : āϚāĻžāĻĒ – ⧍ āύāĻŽā§āĻŦā§°ā§° āĻĒā§ā§°āĻļā§āύ⧋āĻ¤ā§āϤ⧰


1. What is pressure ? āϚāĻžāĻĒ āĻ•āĻŋ ?


Ans: Pressure is the force acting per unit area. āωāĻ¤ā§āϤ⧰: āϚāĻžāĻĒ āĻšā§ˆāϛ⧇ āĻāĻ•āĻ• āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāϤ āĻĒā§ā§°āϝāĻŧā§‹āĻ— āϕ⧰āĻž āĻŦāϞāĨ¤


2. Write the formula of pressure. āϚāĻžāĻĒā§° āϏ⧂āĻ¤ā§ā§° āϞāĻŋāĻ–āĻžāĨ¤


Ans: P = F/A, Pressure is equal to force divided by area.


āωāĻ¤ā§āϤ⧰: āϚāĻžāĻĒ = āĻŦāϞ ÷ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāĨ¤


3. What is the SI unit of pressure ? āϚāĻžāĻĒā§° SI āĻāĻ•āĻ• āĻ•āĻŋ ?


Ans: The SI unit of pressure is Pascal (Pa). āωāĻ¤ā§āϤ⧰: āϚāĻžāĻĒā§° SI āĻāĻ•āĻ• āĻšā§ˆāϛ⧇ Pascal (Pa)āĨ¤


4. How can pressure be increased ? āϚāĻžāĻĒ āϕ⧇āύ⧇āĻ•ā§ˆ āĻŦ⧃āĻĻā§āϧāĻŋ āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋ ?


Ans: Pressure can be increased by increasing force or decreasing area. āωāĻ¤ā§āϤ⧰: āĻŦāϞ āĻŦ⧃āĻĻā§āϧāĻŋ āϕ⧰āĻŋ āĻŦāĻž āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ āĻ•āĻŽāĻžāχ āϚāĻžāĻĒ āĻŦ⧃āĻĻā§āϧāĻŋ āϕ⧰āĻŋāĻŦ āĻĒāĻžā§°āĻŋāĨ¤


5. Why do sharp knives cut easily ? āϧāĻžāϰāĻžāϞ⧋ āϛ⧁⧰⧀āϝāĻŧ⧇ āϏāĻšāĻœā§‡ āĻ•āĻŋāϝāĻŧ āĻ•āĻžāĻŸā§‡ ?


Ans: Sharp knives have smaller area, so they produce greater pressure. āωāĻ¤ā§āϤ⧰: āϧāĻžā§°āĻžāϞ⧋ āϛ⧁⧰⧀⧰ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ āĻ•āĻŽ āĻšāϝāĻŧ, āϏ⧇āϝāĻŧ⧇āĻšā§‡ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āϕ⧰⧇āĨ¤


Pressure – 5 Marks Questions with Answers : āϚāĻžāĻĒ – ā§Ģ āύāĻŽā§āĻŦā§°ā§° āĻĒā§ā§°āĻļā§āύ⧋āĻ¤ā§āϤ⧰


1. Define pressure and write its formula and SI unit. āϚāĻžāĻĒā§° āϏāĻ‚āĻœā§āĻžāĻž āĻĻāĻŋāϝāĻŧāĻž āφ⧰⧁ āχāϝāĻŧāĻžā§° āϏ⧂āĻ¤ā§ā§° āφ⧰⧁ SI āĻāĻ•āĻ• āϞāĻŋāĻ–āĻžāĨ¤


Ans: Pressure is the force acting per unit area.


Formula: P = F/ASI unit: Pascal (Pa)


āωāĻ¤ā§āϤ⧰: āϚāĻžāĻĒ āĻšā§ˆāϛ⧇ āĻāĻ•āĻ• āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞāϤ āĻĒā§ā§°āϝāĻŧā§‹āĻ— āϕ⧰āĻž āĻŦāϞāĨ¤ SI āĻāĻ•āĻ•: Pascal (Pa)


2. Explain how area affects pressure. āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ⧇ āϚāĻžāĻĒāĻ• āϕ⧇āύ⧇āĻ•ā§ˆ āĻĒā§ā§°āĻ­āĻžā§ąāĻŋāϤ āϕ⧰⧇ āĻŦā§āϝāĻžāĻ–ā§āϝāĻž āϕ⧰āĻžāĨ¤


Ans: Pressure is inversely proportional to area. If the area decreases, pressure increases. If the area increases, pressure decreases. āωāĻ¤ā§āϤ⧰: āϚāĻžāĻĒ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ⧰ āĻŦāĻŋāĻĒā§°ā§€āϤ āϏāĻŽāĻžāύ⧁āĻĒāĻžāϤāĻŋāĻ•āĨ¤ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ āĻ•āĻŽāĻŋāϞ⧇ āϚāĻžāĻĒ āĻŦ⧃āĻĻā§āϧāĻŋ āĻĒāĻžāϝāĻŧ āφ⧰⧁ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ āĻŦ⧃āĻĻā§āϧāĻŋ āĻĒāĻžāϞ⧇ āϚāĻžāĻĒ āĻ•āĻŽā§‡āĨ¤


3. Why do camels have broad feet ? āωāϟ⧰ āĻ­ā§°āĻŋ āĻŦāĻšāϞ āĻ•āĻŋāϝāĻŧ āĻšāϝāĻŧ ?


Ans: Camels have broad feet to reduce pressure on sand. Larger area reduces pressure and prevents sinking. āωāĻ¤ā§āϤ⧰: āωāϟ⧰ āĻ­ā§°āĻŋ āĻŦāĻšāϞ āĻšāϝāĻŧ āϝāĻžāϤ⧇ āĻŦāĻžāϞāĻŋāϤ āϚāĻžāĻĒ āĻ•āĻŽ āĻšāϝāĻŧāĨ¤ āĻ…āϧāĻŋāĻ• āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ⧇ āϚāĻžāĻĒ āĻ•āĻŽāĻžāϝāĻŧ āφ⧰⧁ āĻĄā§āĻŦāĻŋ āĻ¯ā§‹ā§ąāĻžāϤ āĻŦāĻžāϧāĻž āĻĻāĻŋāϝāĻŧ⧇āĨ¤


4. Explain why nails have pointed ends. āĻĒ⧇⧰⧇āϕ⧰ āφāĻ—āĻ­āĻžāĻ— āϤ⧀āĻ•ā§āĻˇā§āĻŖ āĻ•āĻŋāϝāĻŧ āĻšāϝāĻŧ āĻŦā§āϝāĻžāĻ–ā§āϝāĻž āϕ⧰āĻžāĨ¤


Ans: Pointed ends have very small area, so greater pressure is produced, making it easier to penetrate objects. āωāĻ¤ā§āϤ⧰: āϤ⧀āĻ•ā§āĻˇā§āĻŖ āφāĻ—āĻ­āĻžāĻ—āϤ āĻ•ā§āώ⧇āĻ¤ā§ā§°āĻĢāϞ āĻ•āĻŽ āĻšāϝāĻŧ, āϏ⧇āϝāĻŧ⧇āĻšā§‡ āĻ…āϧāĻŋāĻ• āϚāĻžāĻĒ āĻ‰ā§ŽāĻĒāĻ¨ā§āύ āĻšāϝāĻŧ āφ⧰⧁ āĻŦāĻ¸ā§āϤ⧁āϤ āϏāĻšāĻœā§‡ āϏ⧋āĻŽāĻžāϝāĻŧāĨ¤


5. Mention two everyday applications of pressure. āϚāĻžāĻĒā§° āĻĻ⧈āύāĻ¨ā§āĻĻāĻŋāύ āĻœā§€ā§ąāύ⧰ āĻĻ⧁āϟāĻž āĻŦā§āĻ¯ā§ąāĻšāĻžā§° āωāĻ˛ā§āϞ⧇āĻ– āϕ⧰āĻžāĨ¤


Ans: i. Sharp knives for cutting (āĻ•āĻžāϟāĻŋāĻŦāϞ⧈ āϧāĻžāϰāĻžāϞ⧋ āϛ⧁⧰⧀),  ii. Syringes for injecting medicine (āĻ”āώāϧ āĻĻāĻŋāĻŦāϞ⧈ syringe)