Light Reflection and Refraction Flashcards

Vocabulary practice flashcards covering fundamental terms, formulas, and laws of light reflection and refraction.

Reflection of Light

The bouncing back of light when it hits a polished surface like a mirror.

Laws of Reflection

(i) Angle of incidence equals angle of reflection ($\angle i = \angle r$). (ii) The incident ray, reflected ray, and the normal all lie in the same plane.

Pole ($P$)

The centre of the reflecting surface of a spherical mirror.

Centre of Curvature ($C$)

The centre of the sphere of which the spherical mirror is a part.

Principal Axis

The straight line joining the pole ($P$) and centre of curvature ($C$) of a mirror; it is normal to the mirror at the pole.

Radius of Curvature ($R$)

The distance $PC$ from the pole to the centre of curvature of a spherical mirror, related to focal length by $R = 2f$.

Concave Mirror

A spherical mirror whose reflecting surface curves inward; also known as a converging mirror.

Convex Mirror

A spherical mirror whose reflecting surface curves outward; also known as a diverging mirror.

Mirror Formula

The mathematical relationship between focal length ($f$), image distance ($v$), and object distance ($u$), given by $\frac{1}{f} = \frac{1}{v} + \frac{1}{u}$.

Magnification ($m$) for Mirrors

The ratio of image height ($h_i$) to object height ($h_o$), given by $m = \frac{h_i}{h_o} = -\frac{v}{u}$.

Convex Lens

A spherical lens that is thick in the middle and thin at the edges; acts as a converging lens.

Concave Lens

A spherical lens that is thin in the middle and thick at the edges; acts as a diverging lens.

Lens Formula

The relationship between focal length ($f$), image distance ($v$), and object distance ($u$) for a lens, given by $\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$.

Magnification ($m$) for Lenses

The ratio of image height ($h_i$) to object height ($h_o$) for a lens, given by $m = \frac{h_i}{h_o} = \frac{v}{u}$.

Power of a Lens ($P$)

The ability of a lens to converge or diverge rays of light, defined as the reciprocal of its focal length in meters ($P = \frac{1}{f\text{ (in m)}}$).

Dioptre ($D$)

The SI unit of power of a lens, corresponding to a lens with a focal length of $1\,\text{m}$ ($1\,\text{D} = 1\,\text{m}^{-1}$).

Refraction of Light

The bending of a light ray when it travels from one medium to another.

Refractive Index ($R.I.$)

A measure of how optically dense a medium is, represented by the ratio of the speed of light in the first medium to that in the second medium ($n_{21} = \frac{v_1}{v_2}$).

Absolute Refractive Index

The refractive index of a medium when the first medium is vacuum or air, given by $n = \frac{c}{v}$, where $c$ is the speed of light in vacuum.

Laws of Refraction

(i) The incident ray, normal, and refracted ray all lie in the same plane. (ii) The ratio of the sine of angle of incidence to the sine of angle of refraction is constant for a given pair of media.

Snell's Law

The law stating that $\frac{\sin(i)}{\sin(r)} = \text{constant}$, or $n_1 \sin(i) = n_2 \sin(r)$.

Power of Lens Combination

The net power ($P$) of lenses placed in contact is the algebraic sum of individual powers: $P = P_1 + P_2 + \dots$