Physics

Electric potential, potential difference, and capacitors

Electric potential is the amount of work done to bring a unit positive charge from infinity to a point in an electric field.
It is a scalar quantity and is measured in volts (V).
The formula for electric potential due to a point charge is \( V = k \frac{q}{r} \), where \( q \) is the charge and \( r \) is the distance.
The reference potential is usually taken as zero at infinity.
Positive charges create regions of high potential, and ne

Electric charge is a fundamental property of matter that causes it to experience a force in an electric field.
There are two types of charges: positive and negative.
Like charges repel each other, and unlike charges attract each other.
Charge is measured in coulombs (C).
Quantization of charge states that charge exists in discrete packets, as multiples of the elementary charge e (1.6 × 10^-19

Anti-reflective coatings reduce glare by minimizing reflection from surfaces like glasses and lenses.
They use the principle of destructive interference to cancel out reflected light.
Commonly applied on camera lenses, microscope lenses, and eyeglasses.
Improves the transmission of light, enhancing clarity and visibility.

Interference occurs when two or more waves overlap, resulting in a new wave pattern.
It can be constructive (amplitudes add) or destructive (amplitudes subtract).
The condition for constructive interference is that the path difference is an integer multiple of the wavelength (nλ).
The condition for destructive interference is that the path difference is an odd multiple of half the wavelength ((n + 1/2)λ).
Examples include the Young’s double-s

Primary colors of light are red, green, and blue (RGB).
These colors are called primary because they cannot be produced by combining other colors of light.
When combined in equal proportions, they produce white light.
Primary colors are used in devices like TVs, monitors, and projectors for color mixing.
The RGB model is based on the additive color theory.

Scattering of light occurs when light interacts with particles in a medium and is deflected in different directions.
The intensity of scattered light depends on the wavelength of light and the size of the particles.
Shorter wavelengths (blue and violet) are scattered more than longer wavelengths (red and yellow).
This phenomenon is described by Rayleigh scattering for small particles.
When particles are compar

Dispersion is the phenomenon where white light splits into its constituent colors when it passes through a prism.
It occurs due to the variation in the refractive index of the material for different wavelengths of light.
The order of colors in the visible spectrum is: Violet, Indigo, Blue, Green, Yellow, Orange, Red (VIBGYOR).
Isaac Newton was the first to demonstrate dispersion using a glass prism.
The angle of deviation is

The human eye is a natural optical instrument that enables vision.
It consists of components like the cornea, lens, retina, iris, and optic nerve.
The lens focuses light onto the retina, where the image is formed.
The ability to focus on objects at varying distances is due to the process of accommodation.
Common defects include:
- Myopia (short-sightedness): Corrected with concave lenses.

The lens formula is given by 1/f = 1/v - 1/u, where:
- f: Focal length of the lens
- v: Image distance
- u: Object distance
This formula is applicable for both convex and concave lenses.
The sign convention depends on the position of the object and the nature of the lens.
Convex lenses (converging lenses) have positive focal lengths, while concave lenses (diverging

A mirror is a reflective surface that forms images by reflecting light.
Plane mirrors produce upright, virtual images with the same size as the object.
Curved mirrors are classified as concave or convex based on the direction of curvature.