Solutions of physics class test-4 of class 6

 1.A force of 10 Newton acts on a body in the upward direction and a force of 12 Newton acts on it in the downward direction .find the resultant of the forces acting on the body?

Ans. A force of 10 Newton acts on a body in the upward direction and a force of 12 Newton acts on it in the downward direction.

So, 12N - 10N = 2N in downward direction.

2.Two forces of 9 Newton and 7 Newton acts on a body to the left while another force of 16 Newton acts on it to the right .find the resultant of the forces?

Ans.9N + 7N = 16 N acts to the left side.

16N = 16 N acts to the right side.

Resultant force is zero.

3.A body is moving downwards. Forces of 20 Newton and 20 Newton act on it upwards, forces of 25 Newton and 20 Newton act on it downwards. Will its peed 

Ans.20 N + 20N = 40N acts upwards.

25N + 20 N = 45N acts downwards

4.Which of the following is a contact force?

Ans. Tension force.

5.A charged comb picks of bits of paper because of

Ans. Electrostatic force.

6.In which of the following cases is friction a disadvantages to us

Ans.Parts of a machine rubbing against each other.

7.Which of the following increases friction

Ans.treads on a tyre

8.A Boat is streamlined to reduce the resistance to motion offered

Ans. By water.

9.The friction does not depends on

Ans . Mass of the body.

10.The shape of a car is streamlined to decrease friction with

Ans . Air

11.The non contact forces in magnitude depend on the distance of separation. When distance of separation is doubled the magnitude of force becomes

Ans( 1/4) th of initial force 

12.Which of the following statement is incorrect

Ans.The unit of weight is kilogram.

13.Friction is not decreased if

Ans.the surfaces are made dry

14.An Apple falls downward because of 

Ans.None of these.

15.A force to be expressed correctly requires

Ans.Both the magnitude and direction

16.A Force does not change

Ans.Mass of the body.

17.The frictional force acts in the direction of

Ans.Opposite to the motion of the body.

18.Friction is reduced by

Ans.Making the surfaces wet.

19.Which one among the following option is odd one:

Ans.Gravitational force.

20.A body needs a force X just to start motion on a surface a force Y to continue its motion and a force Z to roll on the surface then

Ans. Y>Z