Physics M.C.Q (1 Marks)

Charge is given by the relation, $q = I \times t$
so its unit is ampere $-$ sec

$\text{F}=\frac{\text{K.}(\text{q}_1\times\text{q}_2)}{\text{r}^2}$
is given by Coulomb’s Law.

A scalar quantity is a quantity with magnitude only but no direction. But a vector quantity possesses both magnitude and direction. An electric field has a very specific direction $($away from a positive charge or towards a negative charge$)$. Hence electric field is a vector quantity. Moreover, we have to use a vector addition for adding two electric fields.

As the electric field inside the spherical conductor has to be zero the equal and opposite charges will be distributed on the conductor surface such that the induced electric field counters the electric field due to negative charge. For negative charges will be distributed on right and positive on left side
As the spherical region is on right side q inside $< 0.$

The charge will be distributed uniformly over the surface of the bubble by symmetry.
As we know, they want to step much farther apart, as charges repel, the only path outward, taking with them the soap surface.
At the same point, the rise in the restored force of the soap film $($surface tension$)$ would be equal and contrary to the electrostatic force, which will result in a new $($larger$)$ radius of equilibrium.
Because of the ionic similarities, this can happen to both positive and negatively charged bubbles.Therefore, when a negative charge is given to the soap bubble, then its radius will increase.

The concept of solid angle is a natural extension of two$-$dimensional plane angle to three$-$dimensional. It is measured in terms of the unit called steradian, abbreviated as sr.

Electrostatic force is the phenomenon that results from slow$-$moving or stationary electrical charges. Specifically, electrostatic force is the physical reaction that holds together the electromagnetic field created by subatomic particles, such as electrons and protons. In order for electrostatic forces to remain cohesive, these particles need to independently maintain both positive and negative charges and react to each other accordingly.
When a balloon is rubbed with a cloth, the electrons from the atoms of the cloth enter the atoms of the balloon and the number of electrons in the atoms of balloon becomes more than the number of protons. Because of that, there is a negative charge in the balloon, and in the cloth the number of electrons in its atoms become less than the number of protons, so it's positively charged.
Therefore, due to this electrostatic force, the balloon sticks to the wall.

Coulomb stated that the force $(F)$ of attraction or repulsion between two points charges $q_1$​ and $q_2$ separated by a distance $r$ is proportional to the product of the magnitude of the two charges, and inversely proportional to the square of the distance of separation between them. i.e., $\text{F}\propto\frac{\text{q}_1\text{q}_2}{\text{r}^2}$

Force will decreases because when medium is inserted between then it will reduces the forces by its permitivity. the force becomes
$\text{Fe}_\text{m}=\frac{\text{Fe}}{\in_\text{r}}$

Water is dipolar in nature. Hence when water enters an electric field, the molecules rearrange themselves.
The case $1$ in the figure, where a positively charged rod is brought near the water, the negative charge moves towards the rod and positive charge moves away from the rod.
Hence, the attractive force is greater than the repulsive force and as a result, the water stream bends towards the rod.
To the contrast, in case $2$, when a negatively charged rod is brought near the water, the molecules rearrange such that positive charge moves towards the rod and the negative charge moves away from it as shown in the figure.
In this case also, the attractive forces dominate the repulsive forces, and hence, the stream still bends towards the rod.

If both the charges are of the same polarity $($maybe of unequal magnitude$)$, there must be a point in between them where the electric field intensities of the charges are of equal magnitude and in opposite direction. Hence they balance each other and the net field intensity must be zero. But if the charges are of opposite polarities their field intensities aid each other and net field intensity can never be zero.

The value of $\text{K}=\frac{1}{4\pi\in_0}=8.854\times10^{-12}\text{C}^2\text{N}^{-1}\text{m}^{-2}$
Where $ε0​$ is permittivity of free space.

The magnitude of electric force between electron and proton is given by $\text{F}=\frac{1}{4\pi\in_0}\frac{\text{e(-e)}}{\text{d}^2}$
The force on each of them is equal in magnitude and is attractive.
The acceleration of a species is given by $\text{a}=\frac{\text{F}}{\text{m}}$