A small bob of mass 100 mg and charge +10 Β΅C is connected to an insulating string of length 1 m. It is brought near to an infinitely long non-conducting sheet of charge density \( \sigma \) as shown in figure. If the string subtends an angle of 45Β° with the sheet at equilibrium, the charge density of sheet will be :
Consider two infinitely large plane parallel conducting plates as shown below. The plates are uniformly charged with a surface charge density \( +\sigma \) and \( -\sigma \). The force experienced by a point charge \( +q \) placed at the mid point between the plates will be:
If $ \sum_{r=0}^{10} \left( 10^{r+1} - 1 \right)$ $\,$\(\binom{10}{r} = \alpha^{11} - 1 \), then $ \alpha $ is equal to :
Given three identical bags each containing 10 balls, whose colours are as follows:
Bag I | 3 Red | 2 Blue | 5 Green |
Bag II | 4 Red | 3 Blue | 3 Green |
Bag III | 5 Red | 1 Blue | 4 Green |
A person chooses a bag at random and takes out a ball. If the ball is Red, the probability that it is from Bag I is $ p $ and if the ball is Green, the probability that it is from Bag III is $ q $, then the value of $ \frac{1}{p} + \frac{1}{q} $ is:
Electrostatics is the branch of physics that deals with the study of stationary electric charges and their interactions. It involves the study of electric fields, electric charges, electric potential, and electric potential energy.
Electric charges are either positive or negative, and like charges repel while opposite charges attract. Electric charges can be generated by the transfer of electrons from one material to another, by contact between charged objects, or by induction, which involves the creation of an electric field that causes a separation of charges in a conductor.
Electric fields are regions in space around a charged object where an electric force is exerted on other charged objects. The strength of the electric field depends on the distance from the charged object and the magnitude of the charge.
Electric potential is a measure of the work required to move a unit charge from one point to another in an electric field. Electric potential energy is the energy that a charged object possesses due to its position in an electric field.
The behavior of electric charges and fields is described by Coulomb's law, which states that the force between two point charges is proportional to the product of their charges and inversely proportional to the square of the distance between them.
Electrostatics has numerous applications in technology, including in the design of electrical and electronic devices, such as capacitors and semiconductors. It also plays a vital role in everyday life, such as in the generation and distribution of electric power and in the functioning of the human nervous system.