CHSE Odisha Elective Physics flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Coulomb's law

The electrostatic force between two point charges is proportional to the product of the charges and inversely proportional to the square of their separation, acting along the line joining them.

Dielectric constant

The ratio of the capacitance of a capacitor with a dielectric filling its gap to its capacitance with vacuum; it also divides the Coulomb force between charges in that medium.

Drift velocity

The average velocity acquired by free electrons along a conductor under an applied field, given by I = nAev_d and typically of order 10⁻⁴ m/s.

Wheatstone bridge balance

A four-arm network is balanced, with no current through the galvanometer, when the ratio of two adjacent arms equals the ratio of the other two arms.

Ampere's circuital law

The line integral of magnetic field around any closed path equals the permeability of free space times the total current enclosed by that path.

Tangent galvanometer

An instrument in which a small compass needle at the centre of a horizontal coil deflects so that the current is proportional to the tangent of the deflection angle.

Lenz's law

The direction of an induced current is such that its magnetic effect opposes the change in magnetic flux that produced it, ensuring conservation of energy.

Resonance in series LCR

The condition where inductive and capacitive reactances cancel, impedance equals resistance alone, current is maximum, and the resonant frequency is one over two pi root LC.

Critical angle

The angle of incidence in the denser medium for which the refracted ray grazes the interface; beyond it total internal reflection occurs, and its sine equals the reciprocal of refractive index.

Prism minimum deviation

The symmetric passage of light through a prism where the angle of deviation is least; the refractive index follows from the prism angle and this minimum deviation.

Fringe width

The separation between consecutive bright or dark fringes in Young's double-slit pattern, equal to wavelength times screen distance divided by slit separation.

Brewster's law

When light strikes a transparent surface at a particular angle, the reflected light is completely plane polarised, and the tangent of that angle equals the refractive index.

Stopping potential

The reverse voltage applied to a photocell that just reduces the photoelectric current to zero; it measures the maximum kinetic energy of emitted electrons.

de Broglie wavelength

The wavelength associated with a moving particle, equal to Planck's constant divided by its momentum; for electrons it varies inversely with the square root of accelerating voltage.

Bohr radius

The radius of the first allowed electron orbit in hydrogen, about 0.53 angstrom; radii of higher orbits increase as the square of the principal quantum number.

Half-life

The time in which half the nuclei of a radioactive sample decay; it equals the natural logarithm of two divided by the decay constant.

Zener diode

A heavily doped diode operated in reverse breakdown, where the voltage stays nearly constant over a wide current range, so it serves as a voltage regulator.

Transistor current gain beta

The ratio of collector current to base current in a common-emitter configuration; it relates to alpha as beta equals alpha divided by one minus alpha.

Moment of inertia

The rotational analogue of mass, equal to the sum of mass times square of distance from the axis; it depends on the axis chosen.

Rolling without slipping

Motion in which the contact point has zero velocity relative to the surface, so linear speed equals angular speed times radius and kinetic energy includes both translational and rotational terms.

Escape velocity

The minimum speed needed for a body to leave a planet's gravitational field without further propulsion, equal to the square root of twice GM divided by radius.

Young's modulus

The ratio of longitudinal stress to longitudinal strain within the elastic limit, a measure of the stiffness of a solid material.

Time period of simple pendulum

The time for one complete oscillation, equal to two pi times the square root of length divided by acceleration due to gravity, for small swings.

Damped oscillation

Oscillation in which amplitude decreases exponentially with time because of a velocity-dependent resistive force, while the frequency is slightly reduced.

Beat frequency

The number of intensity maxima heard per second when two sound waves of slightly different frequency superpose; it equals the difference of the two frequencies.

Doppler effect in sound

The apparent change in frequency heard when source and observer move relative to each other; approach raises the pitch and recession lowers it.

Degrees of freedom

The number of independent ways a gas molecule can store energy; it fixes the ratio of specific heats through gamma equal to one plus two over f.

Carnot efficiency

The maximum efficiency of a reversible heat engine working between two reservoirs, equal to one minus the ratio of sink to source absolute temperature.

Vernier least count

The smallest measurement a vernier calliper can read, equal to one main scale division minus one vernier scale division, commonly 0.1 mm.

Metre bridge formula

The unknown resistance equals the known resistance multiplied by the balancing length measured from the unknown gap divided by the remaining length of the wire.

Power factor

The cosine of the phase angle between alternating voltage and current; it equals resistance divided by impedance and determines the real power consumed.

Gauss's law

The total electric flux through a closed surface equals the enclosed charge divided by the permittivity of free space, regardless of the surface shape.