Q.No.12.9: - Do electrons tend to go to region of high potential or of low potential.

Q.No.12.9: - Do electrons tend to go to region of high potential or of low potential.

Ans: - By convention we use positive potential as a high and negative potential as low potential. So according to this convention we can say that electrons which have negative charge tend to go to the region of high potential (positive) from low potential (negative).

Q.No.12.6: - If a point charge q of mass m is released in a non-uniform electric field, will it make a rectilinear motion?

Q.No.12.6: - If a point charge q of mass m is released in a non-uniform electric field, will it make a rectilinear motion?

Ans: - A rectilinear motion means a motion along a straight line. If a point charge q of mass m is placed at any point in the non-uniform electric field. Suppose this field is caused by a positive point charge then the charge will experience a repulsive force (as the force will exert on the charge along the line joining the two charges) and the charge will follow a straight path which makes a rectilinear motion.

Q.No.12.3: - How can you identify that which plate of a capacitor is positively charged?

Q.No.12.3: - How can you identify that which plate of a capacitor is positively charged?

Ans: - For this purpose we can use Gold Leaf Electroscope (GLE). We bring the disc of a positively charged electroscope close to the plate of the capacitor. If the divergence of the gold leaf increases, then the plate is positively charged and if the divergence in the leaf decreases, then the plate is negatively charged.

                                                  Or

Rub together a plastic rod and a piece of fur, both initially uncharged, the rod acquires a negative charge (since it takes electrons from the fur) and the fur acquires a positively charge of the same magnitude ( since it has lost as many electrons as the rod has gained). Now bring the plastic rod to one of the capacitors plate is there is a repulsion between the plastic rod and the capaticor’s plate then it means that the plate is negatively charged and the other has positive charge and vice versa.

Q.No.12.1: - The potential is constant throughout a given region of space. Is the electrical field zero or nonzero in this region? Explain.

Q.No.12.1: - The potential is constant throughout a given region of space. Is the electrical field zero or nonzero in this region? Explain.

Ans: - The electric field has a relation with change in electrical potential which is

                                                E   =   -ΔV/Δr

In this case ΔV is the change in electrical potential and if the change in potential is zero then E will be zero and ΔV will be zero only when there is no change in electrical potential. This is given in question that electrical potential is constant throughout the given region of space hence, E = 0 when ΔV=0

Mathematically,

                                  E   =   -ΔV/Δr   =    -0/Δr    =   0