Related InterviewSolutions

• As the height of liquid in a column increases, the amount of pressure will be: (a) Less (b) More (c) No change (d) None of the above
• The unit of pressure is : (a) newton (b) meter/sec (c) newton/metre2 (d) joule
• Why is the knife used for cutting vegetable sharper?
• Define pressure?
• Place the sharp head of a nail towards a wooden block it lightly by hammer. nail does not pierce the wooden block by light blow of the hammer. Using same hammer, now strike hard. Why does nail penetrate into wooden block this time? Due to the hard strike by the hammer,more force is applied due to which more pressure is applied on the object.It is clear from both the above activities that magnitude of pressure depends on applied force. When the applied force is different on the same area than the pressure is also different on the object.1. Why does nail penetrate into wooden block this time?2. Why pointed nail gets into the wooden block easily, as compared to a thicker nail?
• Put a brick on sponge as show in Figure . Now, put the brick vertical on sponge. The applied force is equal on sponge in both situations.However, we see that sponge squeezes more in vertical position of brick. In which situation, the contract area between sponge and brick is less ?If the area is reduced and value of force is kept constant then pressure increases. This is the reason why the balloon is punctured by sharp pin head and sponge squeezes more in vertical position of brick.We may say that the value of pressure depends on the contact area of object. When contact area is reduced pressure increases.1. In which situation, contact area of the brick and the sponge is less?2. Why sponge gets more depressed when brick is made to stand on it?
• Take two balloons filled with air.Puncture one balloon through flat head of pin as shown in Figure and puncture the second balloon through sharp head of the same pin as shown in figureIn which situation balloon punctured easily?
• Place two books on your palm. What do you feel ? Now,remove one book.What difference do you feel now than in the previous position ? why do you feel more comfortable in second situation than previous one ? We feel more pressure due to more weight(force) in the first situation?1. What do you feel?2. What difference do you feel now in the to previous position?3. Why do you feel more comfort able in second situation then previous one?
• Take a stone. Hold it and then dip it into water. Now, gradually take it out from water. What do you feel? you will find the weight of the held stone is less until it remains inside water but weight increases as it comes out of water.By this we know that the an upward force acts on an object when it is inside water. Similarly, your body appears light when you swim in water.So, we can say that-An upward force acts on objects submerged in liquid which is known as Buoyant force. This property of liquids  is Buoyancy.1. What do you experience?2. Why stone appears to weigh less when immersed in water?3. What do you call an upward force exerted on any object, when in water?4. What do you call the buoyant force exerted by the liquid?
• Take a plastic bottle and make three same sized holes A,B,C at different heights and close them with a tape as in figure. Fill the plastic bottle with water coming out of the holes. From which hole water drops at a greater distance ? The height of the water column above hole A is low i.e., the depth from surface is low whereas the height of the water column above hole C is more. Due to low pressure at hole A, water drops at a shorter distance an due to high pressure at hole C, water drops a greater distance. Thus1. From which hole, water flows at a far distance?2. Why does water flows at a far distance from hole C?3. Why does water flow at a near distance from hole A?