Advertisements
Advertisements
प्रश्न
Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain.
Advertisements
उत्तर
When we take off our sweaters in winter, we hear a crackling sound. This is because removing our sweater acquires charge due to friction between the sweater and our body. As a result, we hear a crackling sound from the sweater.
APPEARS IN
संबंधित प्रश्न
Friction depends on the ______ of surfaces.
A charged glass rod attracts a charged plastic straw.
Fill in the blank.
We use ball bearings to .................. the friction.
Name the two kinds of forces in nature.
When you apply brakes, the bicycle stops and the rim of the wheel becomes hot? Explain the reason.
Define sliding friction
A body needs a force F1 just to start moving on a surface, a force F2 to continue its motion and a force F3 to roll on the surface. What is
- the static friction
- sliding friction and
- rolling friction? State whether F2 is equal, less than or greater than (1) F1 and (2) F3.
State if the following statement is true or false. Correct the statement if it is false.
Like charges always attract each other.
Fill in the blank.
More the roughness of a surface, greater is the ........................
Fill in the blank.
The force of friction acting between two bodies in contact while at rest is known as ................ friction.
Tick the most appropriate answer
Friction always
Fill in the blank
Rolling friction is ............. than sliding friction.
State if the following statement is true or false. Correct the statement if it is false.
Friction helps us to grip the objects in our hand.
State if the following statement is true or false. Correct the statement if it is false.
Friction is offered by all the three states of matter.
Rolling friction is slightly greater than sliding friction.
Complete the analogy.
Knot in a thread : _____ friction : : Ball bearing : _____ friction
Is there any possibility of making a special device to measure the magnitude of friction directly?
We have two identical metal sheets. One of them is rubbed with sand paper and the other with ordinary paper. The one rubbed with sand paper shines more than the other. Give reason.
Analogy
Objects placed at rest on earth: ______:: Bodies slide over the surface on other body: ______.
