Question

what is right hand thumb rule in vector.

plz guys i want in detail.

plzzz in detail.

Answer 1

For that, we need the right hand rule. To use the right hand rule, you first have to hold up your right hand. ... Now, rotate your hand so that your index finger points in the direction of vector a and your middle finger points in the direction of vector b. Your thumb will point in the direction of the cross product a x b.

Answer 2

Easy one first.
The right hand rule is just a convention - a standard way of doing it. In the same way as the +x axis on a graph is taken as going right and the -x axis goes left. Everyone does it that way but it could be done the other way.
Providing the convention is used consistently, there is no ambiguity. Historically a right hand rule, rather rather than a left hand, was adopted by mathematicians and physicists - presumably because more people are right handed.
There is no proof - like there is no proof that the +x axis should go to the right.
______________________
The cross product was developed because in some situations 2 vectors give rise to a 3rd vector perpendicular to both. It is widely used in physics and engineering.
For example torque is the cross product of the position vector and force vector, the energy flow vector in an electromagnetic waves is the cross product of the electric field vector and magnetic field vector. There are many others.

Hope it help.