We are not normally aware of the gravitational or electric force between two orgdinary objects. What is the reason in each case? Give an example where we are aware of each one and why.
Can any one help me in this ?

Gravitational forces are due to mass of the object. Any object which has mass is attracted by another object which has mass.

The force of attraction between two objects of masses m1 and m2, separated by a distance r is given by:
F = Gm1 X m2 /r2

,  where G is the universal gravitational constant.

For all objects on surface of earth, this force acts as gravity and pulls the objects towards centre of earth.
Since the force depends on the mass of objects, any two objects, say two persons a and b, would also attract each other with a force whose value is as worked out by formula above.

However these persons are also attracted individually by the earth.

Since the mass of earth is much more than either of the persons, the force of gravity between the earth and persons a and b is much more than the attractive force between a and b. Hence the force of attraction between a and b, though present is not visibly felt.

A visible example of this fact is the forces acting on a space craft. When the spacecraft takes off from earth, it revolves around the earth being under the gravitational forces of earth. As it moves outwards towards moon, it comes under gravitational force of moon and starts to revolve around it.

Also another example is when you throw something upwards, or you jump up, the gravitational forces pull the object or the person down. You are being attracted by the mass of the earth which exerts the downward pull.

All objects in the universe are made of electric particles like protons and electrons which possess positive and negative charges. All bodies are electrically neutral as number of negative and positive charges are equal in each body.

However when a body is electrically charged due to gain or loss of +ve or –ve charged particles, then a electrical force can be experienced. The best and general example is that if we take a plastic comb and rub it on our hair, it gets electrically charged. It can then attract small pieces of paper due to electrical forces of attraction.
The magnitude of the electrostatic force (F) on a charge (q1) due to the presence of a second charge (q2), is given by
F = ke q1 X q2 / r2

where r is the distance between the two charges and ke a proportionality constant.  A positive force implies a repulsive interaction, while a negative force implies an attractive interaction.
Also when we rub synthetic clothes, they get charged and stick to your body due to the electrical forces of attraction.

I hope I have explained everything above.

Thanks. Great information.

good to see that lots of people have interest in physics