
Match Column-I with Column-II and choose the correct option:
| Column-I (Minerals) | Column-II (Features) | ||
|---|---|---|---|
| A. | Copper | (i) | Used in manufacturing of steel and plants |
| B. | Bauxite | (ii) | Used in electric and electronic industries |
| C. | Mica | (iii) | Used in electric cables and utensils |
| D. | Manganese | (iv) | Used in aluminium production |
Choose the correct answer from the options given below:
Give reasons:
(i) The sky appears dark to passengers flying at very high altitudes.
At very high altitudes, passengers are above the atmosphere where there is less scattering of sunlight. As a result, they do not see the scattered blue light and the sky appears dark, similar to the condition experienced by astronauts in space.
(ii) 'Danger' signal lights are red in color.
Electric potential, also known as voltage, is a scalar quantity that measures the amount of electric potential energy per unit charge in an electric field. It is denoted by the symbol V and is measured in volts (V).
The electric potential at a point in an electric field is defined as the amount of work done per unit charge to bring a positive test charge from infinity to that point. The electric potential at a point is also equal to the potential energy per unit charge of a positive test charge placed at that point.
Electric potential is a fundamental concept in electromagnetism and is used to describe the behavior of electric fields and charges. It is also used to calculate the electric potential difference, or voltage, between two points in an electric field.
The electric potential difference between two points is equal to the work done per unit charge to move a positive test charge from one point to the other. The electric potential difference is also equal to the product of the electric field strength and the distance between the two points.
Electric potential has many practical applications, such as in the design and operation of electrical circuits, electric motors, and generators. It is also used in electroplating, electrochemical cells, and other electrochemical processes. Understanding electric potential is crucial for the development and advancement of modern technology.