Physics (Part-VI) (Railway)

• White light is a mixture of Seven colours, also known as VIB gyo R.

• This property results from different speed of each wave length in a medium due to property of refraction of that medium.

• It is also expressed as P = V²/R, where V is the electric potential measured in volts.

• It is also expressed as P = V x I, where P is power, V is voltage, and I is current.

• The focal length of a spherical mirror is half its radius of curvature.

• Thus, R (radiusofcurvature)=2f

∴ F = R/2

• In other words, m v/u, where m is magnification, v is the image height and u is the object height.

• According to the question, v = 2u

• So, m=2u/u = 2

• For a convex lens, if the image formed is real and inverted, the magnification is negative.

• When R₁, R₂, R₃... R resistors are connected in parallel circuit, the equivalent resistance of the circuit is given by 1/R = 1/R₁ + 1/R₂ + 1/R₃ +__ .

• A Positive magnification shows the image is virtual and erect (upright) and a negative one shows the image is real and inverted.

• This is because the magnetic south pole of the earth lies in the geographic north direction and the magnetic north pole of the earth lies in the geographical south direction.

• Thus, as we move away from a current carrying conductor, the intensity of the magnetic field decreases.

• The concave mirrors produce virtual or real, erect or inverted, diminished or the same size depending on the position of the object placed.

• It is taken to be positive for an image to be virtual and erect and negative when the image is real and inverted.

• The angle at which the incident ray passes through the surface of the prism to the normal is called an incident angle and the angle by which the ray emerges out of the prism to the normal is called an emergent ray.

• The angle of deviation d is the angle between the incident ray and emergent ray.