Standard XI Physics Flashcards chp1,2,3,10,11&12

Comprehensive vocabulary flashcards covering major definitions, laws, and physical concepts from the Standard XI Physics textbook.

Fundamental Quantities

Physical quantities that do not depend on any other physical quantities for their measurements, consisting of length, mass, time, temperature, electric current, luminous intensity, and amount of substance.

Derived Quantities

Physical quantities that depend on one or more fundamental quantities and can be expressed in terms of them, such as speed, momentum, and resistance.

Plane Angle ($d\theta$)

The ratio of the arc length of a circle to the radius of the circle, defined as $d\theta = \frac{ds}{r}$ and measured in radians ($\text{rad}$).

Solid Angle ($d\Omega$)

The 3-dimensional analogue of a plane angle, defined as the area of a portion of a spherical surface to the square of its radius, expressed as $d\Omega = \frac{dA}{r^2}$ and measured in steradians ($\text{sr}$).

Parallax

The apparent change in position of an object due to a change in the position of the observer.

Light Year

The distance travelled by light in vacuum in one year, equal to $9.467 \times 10^{15}\,\text{m}$.

Astronomical Unit (AU)

The mean distance between the centre of the Earth and the centre of the Sun, equal to $1.496 \times 10^{11}\,\text{m}$.

Parsec (pc)

The distance from where $1\,\text{AU}$ subtends an angle of $1''$ (1 second of arc), equal to $3.08 \times 10^{16}\,\text{m} \approx 3.26\,\text{light years}$.

Scalar Quantity

A physical quantity that can be completely described by its magnitude alone.

Vector Quantity

A physical quantity that requires both magnitude and direction for its complete description.

Unit Vector

A vector having unit magnitude in a given direction, defined as $\hat{u}_M = \frac{\vec{M}}{|\vec{M}|}$.

Scalar Product (Dot Product)

The product of the magnitudes of two vectors and the cosine of the angle between them, expressed as $\vec{P} \cdot \vec{Q} = P Q \cos(\theta)$.

Vector Product (Cross Product)

A vector whose magnitude equals the product of the magnitudes of two vectors and the sine of the angle between them, given by $\vec{R} = \vec{P} \times \vec{Q}$ with magnitude $P Q \sin(\theta)$.

Projectile Motion

The motion of an object in flight after being thrown with an initial velocity under the influence of Earth's gravity alone.

Centripetal Acceleration

An acceleration directed towards the centre of a circular trajectory that maintains uniform circular motion, with magnitude $a = \frac{v^2}{r} = \omega^2 r$.

Coefficient of Restitution ($e$)

The negative ratio of the relative velocity of separation to the relative velocity of approach in a head-on collision, given by $e = \frac{v_2 - v_1}{u_1 - u_2}$.

Centre of Mass

A hypothetical point at which the entire mass of a body or system can be assumed to be concentrated for describing its translational motion.

Coulomb's Law

The law stating that the electrostatic force between two point charges at rest is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them ($F = \frac{1}{4\pi \varepsilon_0} \frac{q_1 q_2}{r^2}$).

Gauss' Law

The law stating that the net electric flux through any closed Gaussian surface equals the net charge enclosed by the surface divided by $\varepsilon_0$ ($\Phi_E = \oint \vec{E} \cdot d\vec{S} = \frac{Q}{\varepsilon_0}$).

Drift Speed ($v_d$)

The average speed with which free electrons drift in a direction opposite to an applied electric field inside a conductor ($v_d = \frac{J}{n e}$).

Electromagnetic Spectrum

The sequential arrangement of electromagnetic waves ordered by wavelength or frequency into distinct regions from radio waves to gamma rays.

Depletion Region

The region across a p-n junction devoid of free charge carriers, containing only fixed donor and acceptor ions that form a potential barrier.

Systematic Errors

Errors in measurement that are not introduced by chance but arise due to inaccuracies inherent to the system, such as defective calibration or imperfect experimental techniques.

Triangle Law of Vector Addition

The principle stating that if two vectors of the same type are represented in magnitude and direction by two sides of a triangle taken in order, their resultant is represented by the third side drawn from the starting point of the first to the end point of the second.

Average Velocity

The displacement of an object divided by the time interval over which the displacement occurs, expressed as vav=Δr/Δt

Instantaneous Velocity

The limiting value of the average velocity of an object as the time interval approaches zero, given by v=dr/dt

Time of Flight (T)

The total time taken by a projectile from the instant of projection until it reaches the ground, given by T=2usin⁡(θ)/g

Horizontal Range (R)

The maximum horizontal distance travelled by a projectile before hitting the ground, given by R=u2sin(2θ)​/g.

Relative Permittivity (Dielectric Constant)

The ratio of the absolute permittivity of a medium to the permittivity of free space, expressed as εr​=K=ε/0​ε​=Fvac/Fmed​​.

Electric Field Intensity

The electrostatic force experienced per unit positive test charge placed at a given point in space, defined as E=F/q0​​.

Electric Lines of Force

Imaginary curves drawn in an electric field such that the tangent at any point gives the direction of the electric field at that point.

Electric Flux (ΦE)

The dot product of the electric field vector and the area vector over a given surface, represented as ΦE​=∫E⋅dS.

Electric Dipole Moment (p⃗p​)

A vector quantity measuring the strength of an electric dipole, defined as the product of the magnitude of one charge and the distance between the two charges p=q(2l)) directed from negative to positive charge.

Electric Current (I)

The rate of flow of net electric charge across a cross-section of a conductor per unit time, expressed as I=q/t

Ohm's Law

The principle stating that the electric current through a conductor is directly proportional to the potential difference applied across its ends, provided physical conditions remain constant (V=IR).

Electrical Resistivity (ρρ)

A material property representing the resistance per unit length and per unit cross-sectional area of a conductor, given by ρ=RA/l

Temperature Coefficient of Resistance (α)

The fractional change in resistance per unit resistance at a reference temperature per degree change in temperature, defined as α=R−R0/R0​(T−T0​)

Electromotive Force (emf, ε)

The work done per unit charge by a source to move a charge through a complete circuit, given by ε=dW/dq

Magnetic Dipole Moment (m)

A vector quantity measuring the strength of a magnetic dipole, defined for a bar magnet as the product of its pole strength and magnetic length m=qm​(2l)) directed from the south pole to the north pole.

Magnetic Lines of Force

Continuous closed curves representing a magnetic field such that the tangent at any point indicates the direction of the net magnetic field at that point.

Gauss' Law for Magnetism

The law stating that the net magnetic flux through any closed surface is always zero (∮B⋅dS=0), implying isolated magnetic monopoles do not exist.

Magnetic Declination (α)

The angle between the geographic meridian and the magnetic meridian at a given location on Earth.

Angle of Dip (Magnetic Inclination, ϕ)

The angle made by the direction of Earth's resultant magnetic field with the horizontal plane in the magnetic meridian.