Available Answers

1. 1.

   Choose the correct answer :

   1. Force has −
      1. only magnitude
      2. only direction 
      3. both magnitude and direction
      4. neither magnitude nor direction
   2. The SI unit force is −
      1. J
      2. kg/m³
      3. N
      4. Pa
   3. The force exerted by one object on another by virtue of their masses is ---
      1. magnetic force 
      2. electrostatic force
      3. gravitational force
      4. frictional force
   4. Friction ---
      1. produces heat
      2. causes wear and tear 
      3. opposes motion 
      4. All of these
   5. Wheel is made circular because it −
      1. minimises friction
      2. increases friction
      3. decrease pressure on the road
      4. increases area of contact with the road
   6. A cricketer catches a ball. The force that comes into play is −
      1. contact force
      2. gravitational force.
      3. frictional force
      4. All of these
2. 2.

   Fill in the blanks :

   1. The SI unit of force is _________________________.
   2. ____________________________ causes wear and tear.
   3. Gravitational force is always ____________________ in nature.
   4. A stone falling from the roof of a house is an example of _____________________ force.
3. 3.

   Write True (T) or False (F) against the following statements :

   1. When we walk on the ground, friction acts along the direction of motion.
   2. Air offers no friction.
   3. Rolling friction is greater than sliding friction.
   4. Wheel is made circular to minimise friction.
   5. When one body id lying over another body, there is no friction. 
4. 4.

   Match the following :

   Column  A	Column  B
   1. Moon revolves around the Earth.	a. Mechanical force
   2. Iron nails are attracted by magnet.	b. Muscular force
   3. A man lifts a weight.	c. Gravitational force
   4. Crane is used to lift a heavy load.	d. Magnetic force
   5. Balloons move away from each other after they are rubbed against polyester cloth.	e. Frictional force
   6. A man walks on a levelled road.	f. Electrostatic force

    

5. 5.

   With proper reasoning, choose the odd one out :

   1. push, pull, pressure, squeeze 
   2. magnetic force, electrostatic force, frictional force, gravitational force
   3. a worker pulling a cart, a batsman hitting a cricket ball, a leaf falling from a tree, lifting a bucket
   4. using lubricants, using ball bearings, polishing the surfaces, making grooves in tyres
6. 6.

   What is the unit of force?