Physics for SSC CGL Part 7: Miscellaneous topics Measurement units, Scientific Units

Angstrom: For measurement length of light waves.
Barrel: For measuring liquid. 1 barrel = 31.5 gallon or 7326.5 cubic inches.
Cable: For measuring length of cables. 1 cable = 183m.
Carat: Use for measuring precious stones. It also measure purity of gold alloy.
Fathom: It is used for measuring depth of water. 1 fathom = 4 inches.
Knot: for measuring speed of ships.

Physics for SSC CGL Part 6 - Atomic and nuclear physics

Cathode Rays

• Cathode rays, discovered by Sir William Crooke.
• These are travel in straight lines.
• These produce fluorescence.
• These can produce through thin foils of metal and deflected by both electric and magnetic fields.
• These have velocity ranging 1/30th to 1/10th of the velocity of light.

Physics for SSC CGL Part 4 -Total internal reflection, scattering of light, refraction, reflection

TOTAL INTERNAL REFLECTION

• When a ray of light goes from rare medium to denser medium, then as we increase the angle of incident, angle of refraction also increases, the angle of incidence for which angle of refraction become 90 is called critical angle.
• The complete reflection of light ray reaching an interface with less dense medium when angle of incidence exceeds the critical angle is called total internal reflection.

Physics for SSC CGL Part 5 - Thermodynamics, Heat transfer, Simple harmonic motion, pendulum, electric devices

Thermodynamics

Zero Law of thermodynamics: If two bodies A and B are separately in equilibrium with a Body C; then A and B will be in equilibrium with each other.

First Law of thermodynamics: The amount of heat given to the system is used in two ways to increase the temperature of the body and to the external work.

Second Law of thermodynamics: The entropy of system can only increase over time.

Physics for SSC CGL Part 3 b: Human Eye and defects

Human Eye:

Works like a photographic camera. Image is formed at the retina of the eye.

Range of Vision: 25cm to infinity.

Physics for SSC CGL Part 3a : Light, Reflection, plane mirror, concave and convex lens.

LIGHT

• Light is a transverse wave, and an electromagnetic radiation with in certain portion of electromagnetic spectrum.
• Speed of light is (3 lac km per second)  3.00×10⁸ m/s or 3.00×10⁶ km/s.
• Sun takes 8 min 19 sec (499 or ~500 sec).
• Reflected light from Moon takes 1.28 ~ 1.3 sec to reach the Earth.

Physics for SSC CGL part 2: Gravitation, Satellite, Sound wave,

Gravitation
"According to Newton's Universal Law of Gravitation : Every object in the universe attracts every other object with force that is directional proportional to the product of their mass and inversely proportional to the square of the distance between their centre."

g=G*m1*m2/d²  (G= Gravitational constant)
* It is attractive in nature.
* It is the weakest force but is a long range force.

Physics for SSC CGL Part 1: Physical quantities, Newton's law, Linear momentum, Impulse, Friction, Pascals Law, Archimedes' Principle Work, Energy, Power

Physical Quantities
Scalar Quantities: which have only magnitude and no direction. e.g. mass, speed, volume, distance etc.
Vector Quantities: which have both magnitude and direction. e.g. velocity, displacement, momentum, force etc.
Tensor Quantities: which are neither scalar or vector quantities. e.g. Stress, Inertia etc.