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WBJEE Physics - Electromagnetism, Optics and Modern Physics Syllabus

The Physics - Electromagnetism, Optics and Modern Physics syllabus for WBJEE in full: 5 chapters, 15 topics and 45 sub-topics, every one listed below, plus 50 Physics - Electromagnetism, Optics and Modern Physics flashcards with answers.

5Chapters

15Topics

45Sub-topics

50Flashcards

Physics - Electromagnetism, Optics and Modern Physics syllabus: all 5 chapters

Expand any chapter to see its topics and sub-topics.

Oscillations and Waves
3 topics
- Simple Harmonic Motion
  - Equation of SHM and energy
  - Spring and pendulum oscillations
  - Damped and forced oscillations, resonance
- Wave Motion
  - Transverse and longitudinal waves
  - Superposition, interference and beats
  - Standing waves in strings and pipes
- Sound and Doppler Effect
  - Characteristics of sound waves
  - Doppler effect in sound
Electrostatics and Current Electricity
3 topics
- Electrostatics
  - Coulomb's law and electric field
  - Gauss's law and applications
  - Electric potential and potential energy
  - Capacitors and dielectrics
- Current Electricity
  - Ohm's law and resistance
  - Kirchhoff's laws and circuit analysis
  - Wheatstone bridge and potentiometer
  - Heating effect of current
- Thermoelectricity and Chemical Effects
  - Seebeck and Peltier effects
  - Faraday's laws of electrolysis
Magnetism and Electromagnetic Induction
3 topics
- Magnetic Effects of Current
  - Biot-Savart and Ampere's law
  - Force on current carrying conductor
  - Moving coil galvanometer
- Magnetism and Matter
  - Bar magnet and magnetic field
  - Para, dia and ferromagnetism
- Electromagnetic Induction and AC
  - Faraday's and Lenz's law
  - Self and mutual inductance
  - Alternating current and LCR circuits
  - Transformers and resonance
Optics
3 topics
- Ray Optics
  - Reflection at plane and curved surfaces
  - Refraction and total internal reflection
  - Lenses, lens maker's formula and combinations
  - Optical instruments
- Wave Optics
  - Huygens' principle and wavefronts
  - Young's double slit experiment
  - Diffraction and polarization
- Electromagnetic Waves
  - Displacement current and Maxwell's equations
  - Electromagnetic spectrum
Modern Physics and Electronics
3 topics
- Dual Nature and Atomic Physics
  - Photoelectric effect and Einstein's equation
  - de Broglie wavelength
  - Bohr model and atomic spectra
- Nuclear Physics
  - Nuclear structure and binding energy
  - Radioactivity and decay laws
  - Nuclear fission and fusion
- Semiconductor Electronics
  - Intrinsic and extrinsic semiconductors
  - p-n junction diode and rectifiers
  - Transistors and logic gates

WBJEE Physics - Electromagnetism, Optics and Modern Physics flashcards — 50 questions with answers

Define Simple Harmonic Motion (SHM).
SHM is oscillatory motion in which the restoring force (or acceleration) is directly proportional to the displacement from the mean position and always directed toward it: $F = -kx$, so $a = -\omega^{2} x$.
Write the general displacement equation of SHM and identify each symbol.
$x(t) = A\sin(\omega t + \phi)$, where $A$ is amplitude, $\omega$ is angular frequency, $t$ is time, and $\phi$ is the initial phase (phase constant).
How are angular frequency $\omega$, time period $T$, and frequency $f$ related in SHM?
$\omega = 2\pi f = \dfrac{2\pi}{T}$, so $T = \dfrac{2\pi}{\omega}$ and $f = \dfrac{1}{T}$.
In SHM, what are the expressions for velocity and acceleration as functions of displacement $x$?
Velocity: $v = \pm\,\omega\sqrt{A^{2} - x^{2}}$. Acceleration: $a = -\omega^{2} x$. Speed is maximum at $x=0$ and zero at $x = \pm A$.
Where in an SHM cycle are kinetic energy and potential energy maximum?
Kinetic energy is maximum at the mean position ($x=0$); potential energy is maximum at the extreme positions ($x=\pm A$). Total energy stays constant.
Give the expressions for kinetic, potential, and total energy in SHM.
$KE = \frac{1}{2}m\omega^{2}(A^{2}-x^{2})$, $PE = \frac{1}{2}m\omega^{2}x^{2}$, and total energy $E = \frac{1}{2}m\omega^{2}A^{2}$ (constant).
What is the time period of a mass $m$ attached to a spring of force constant $k$?
$T = 2\pi\sqrt{\dfrac{m}{k}}$. It is independent of amplitude and of gravity.
What is the time period of a simple pendulum of length $L$?
$T = 2\pi\sqrt{\dfrac{L}{g}}$, valid only for small angular amplitudes (so $\sin\theta \approx \theta$).
Compare the effective spring constant for two springs $k_1$, $k_2$ in series versus in parallel.
Parallel: $k_{eff} = k_1 + k_2$ (stiffer). Series: $\dfrac{1}{k_{eff}} = \dfrac{1}{k_1} + \dfrac{1}{k_2}$ (softer).
What is a damped oscillation, and how does its amplitude vary with time?
An oscillation in which energy is lost (e.g. to friction), so amplitude decays. For light damping, $x = A_0 e^{-bt/2m}\cos(\omega' t + \phi)$, with damped frequency $\omega' = \sqrt{\omega_0^{2} - \left(\dfrac{b}{2m}\right)^{2}}$.
Distinguish underdamped, critically damped, and overdamped motion.
Underdamped: oscillates with decaying amplitude. Critically damped: returns to equilibrium fastest without oscillating. Overdamped: returns slowly without oscillating.
What is resonance in forced oscillations?
Resonance occurs when the driving frequency equals the natural frequency $\omega_0$ of the system, producing maximum amplitude. Lower damping gives a sharper, higher resonance peak.
What distinguishes free, forced, and damped oscillations?
Free: oscillates at natural frequency with no external force or damping. Damped: amplitude decays due to dissipative forces. Forced: driven by an external periodic force at the driver's frequency.
Define wave motion and state what a mechanical wave transports.
Wave motion is the propagation of a disturbance through a medium (or space) that transfers energy and momentum without net transport of the medium's particles.
Distinguish transverse and longitudinal waves with examples.
Transverse: particle motion is perpendicular to wave propagation (e.g. light, waves on a string). Longitudinal: particle motion is parallel to propagation, forming compressions and rarefactions (e.g. sound).
Write the wave equation $y(x,t)$ for a wave traveling in the $+x$ direction.
$y(x,t) = A\sin(kx - \omega t)$, where wave number $k = \dfrac{2\pi}{\lambda}$ and angular frequency $\omega = 2\pi f$.
State the relation between wave speed, frequency, and wavelength.
$v = f\lambda = \dfrac{\omega}{k}$, where $v$ is wave speed, $f$ frequency, and $\lambda$ wavelength.
What is the speed of a transverse wave on a stretched string?
$v = \sqrt{\dfrac{T}{\mu}}$, where $T$ is the tension and $\mu$ is the linear mass density (mass per unit length).
State the principle of superposition of waves.
When two or more waves overlap, the resultant displacement at any point equals the algebraic (vector) sum of the displacements due to the individual waves.
State the conditions for constructive and destructive interference in terms of path difference.
Constructive: path difference $\Delta = n\lambda$ (phase difference $2n\pi$). Destructive: $\Delta = \left(n+\frac{1}{2}\right)\lambda$ (phase difference $(2n+1)\pi$), where $n = 0,1,2,\dots$

Show the other 30 Physics - Electromagnetism, Optics and Modern Physics flashcards

What are beats and what is the beat frequency?
Beats are periodic variations in loudness from superposition of two waves of slightly different frequencies. Beat frequency $f_{beat} = |f_1 - f_2|$.
What is a standing (stationary) wave and what is the distance between adjacent nodes?
A standing wave forms from superposition of two identical waves traveling in opposite directions; it has fixed nodes and antinodes. The distance between adjacent nodes (or adjacent antinodes) is $\dfrac{\lambda}{2}$.
Give the frequencies of harmonics for a string fixed at both ends of length $L$.
$f_n = \dfrac{n v}{2L}$, $n = 1,2,3,\dots$ All harmonics are present; the fundamental is $f_1 = \dfrac{v}{2L}$.
Give the harmonic frequencies for an open organ pipe (open at both ends) of length $L$.
$f_n = \dfrac{n v}{2L}$, $n = 1,2,3,\dots$ All harmonics are present, like a string fixed at both ends.
Give the harmonic frequencies for a closed organ pipe (closed at one end) of length $L$.
$f_n = \dfrac{(2n-1) v}{4L}$, $n = 1,2,3,\dots$ Only odd harmonics are present; fundamental $f_1 = \dfrac{v}{4L}$.
What are the three characteristics of a musical sound and their physical correlates?
Loudness (depends on amplitude/intensity), Pitch (depends on frequency), and Quality/Timbre (depends on the waveform / number and strength of overtones).
On what does the speed of sound in a gas depend, per Laplace's formula?
$v = \sqrt{\dfrac{\gamma P}{\rho}}$, where $\gamma$ is the adiabatic ratio $C_p/C_v$, $P$ is pressure, and $\rho$ is density. Speed increases with temperature: $v \propto \sqrt{T}$.
How is sound intensity related to amplitude and to distance from a point source?
Intensity $I \propto A^{2}$ (proportional to amplitude squared) and $I \propto \dfrac{1}{r^{2}}$ (inverse-square law from a point source).
State the general Doppler effect formula for the observed frequency of sound.
$f' = f\left(\dfrac{v \pm v_o}{v \mp v_s}\right)$, where $v$ is sound speed, $v_o$ observer speed, $v_s$ source speed; signs are chosen so relative approach increases $f'$.
Using the Doppler formula, what is the observed frequency when the source moves toward a stationary observer?
$f' = f\left(\dfrac{v}{v - v_s}\right)$, which is greater than $f$ (perceived pitch rises as the source approaches).
State Coulomb's law in vector form.
$\vec{F} = \dfrac{1}{4\pi\varepsilon_0}\dfrac{q_1 q_2}{r^{2}}\hat{r}$, the force between two point charges; it is attractive for unlike and repulsive for like charges. $\dfrac{1}{4\pi\varepsilon_0} \approx 9\times10^{9}\,\text{N m}^2/\text{C}^2$.
Define the electric field and give its value due to a point charge.
Electric field is force per unit positive test charge: $\vec{E} = \dfrac{\vec{F}}{q_0}$. For a point charge: $E = \dfrac{1}{4\pi\varepsilon_0}\dfrac{q}{r^{2}}$.
State Gauss's law.
The net electric flux through a closed surface equals the enclosed charge divided by $\varepsilon_0$: $\oint \vec{E}\cdot d\vec{A} = \dfrac{q_{enc}}{\varepsilon_0}$.
Use Gauss's law to give the electric field of an infinite line charge with linear density $\lambda$.
$E = \dfrac{\lambda}{2\pi\varepsilon_0 r}$, directed radially; it falls off as $\dfrac{1}{r}$.
What is the electric field due to an infinite charged plane sheet with surface density $\sigma$?
$E = \dfrac{\sigma}{2\varepsilon_0}$, uniform and independent of distance from the sheet.
What is the electric field inside and outside a uniformly charged conducting spherical shell of charge $Q$ and radius $R$?
Inside ($r<R$): $E = 0$. Outside ($r>R$): $E = \dfrac{1}{4\pi\varepsilon_0}\dfrac{Q}{r^{2}}$, as if all charge were at the center.
Define electric potential and give its value due to a point charge.
Electric potential is work done per unit charge to bring a positive test charge from infinity to a point: $V = \dfrac{W}{q_0}$. For a point charge: $V = \dfrac{1}{4\pi\varepsilon_0}\dfrac{q}{r}$.
What is the relation between electric field and potential?
$\vec{E} = -\nabla V$; in one dimension $E_x = -\dfrac{dV}{dx}$. The field points toward decreasing potential.
Give the electric potential energy of a system of two point charges.
$U = \dfrac{1}{4\pi\varepsilon_0}\dfrac{q_1 q_2}{r}$. It is positive for like charges and negative for unlike charges.
Define capacitance and give the capacitance of a parallel-plate capacitor.
Capacitance $C = \dfrac{Q}{V}$ (charge stored per unit potential). For a parallel-plate capacitor: $C = \dfrac{\varepsilon_0 A}{d}$, where $A$ is plate area and $d$ the separation.
How does inserting a dielectric of constant $K$ affect a capacitor's capacitance?
Capacitance increases by factor $K$: $C = \dfrac{K\varepsilon_0 A}{d}$. The dielectric reduces the internal field by factor $K$ and allows more charge storage.
Give the equivalent capacitance for capacitors in series and in parallel.
Series: $\dfrac{1}{C_{eq}} = \dfrac{1}{C_1} + \dfrac{1}{C_2} + \dots$ (smaller). Parallel: $C_{eq} = C_1 + C_2 + \dots$ (larger).
Give three expressions for the energy stored in a capacitor.
$U = \dfrac{1}{2}CV^{2} = \dfrac{1}{2}QV = \dfrac{Q^{2}}{2C}$.
State Ohm's law and define resistance.
Ohm's law: $V = IR$, the current through a conductor is proportional to the potential difference (at constant temperature). Resistance $R = \dfrac{V}{I}$, measured in ohms ($\Omega$).
How does the resistance of a wire depend on its dimensions and resistivity?
$R = \rho\dfrac{L}{A}$, where $\rho$ is resistivity, $L$ is length, and $A$ is cross-sectional area. $R$ increases with length and decreases with area.
Give the formulas for equivalent resistance in series and in parallel.
Series: $R_{eq} = R_1 + R_2 + \dots$ Parallel: $\dfrac{1}{R_{eq}} = \dfrac{1}{R_1} + \dfrac{1}{R_2} + \dots$
Express current in terms of drift velocity of electrons.
$I = nAev_d$, where $n$ is number density of free electrons, $A$ cross-sectional area, $e$ electron charge, and $v_d$ the drift velocity.
How does the resistivity of a metallic conductor vary with temperature?
It increases approximately linearly: $\rho_T = \rho_0[1 + \alpha(T - T_0)]$, where $\alpha$ is the temperature coefficient of resistivity (positive for metals).
State the relation between terminal voltage, EMF, and internal resistance of a cell.
$V = \varepsilon - Ir$, where $\varepsilon$ is the EMF, $I$ the current, and $r$ the internal resistance. The current delivered is $I = \dfrac{\varepsilon}{R + r}$.
Give the formulas for electric power dissipated in a resistor.
$P = VI = I^{2}R = \dfrac{V^{2}}{R}$. Energy dissipated as heat over time $t$ is $H = I^{2}Rt$ (Joule heating).

WBJEE Physics - Electromagnetism, Optics and Modern Physics FAQ

What is in the WBJEE Physics - Electromagnetism, Optics and Modern Physics syllabus?

WBJEE Physics - Electromagnetism, Optics and Modern Physics is split into 5 chapters: Oscillations and Waves, Electrostatics and Current Electricity, Magnetism and Electromagnetic Induction, Optics and Modern Physics and Electronics. Together they contain 15 topics and 45 sub-topics.

How many chapters are in WBJEE Physics - Electromagnetism, Optics and Modern Physics?

5 chapters, containing 15 topics and 45 sub-topics. The largest chapter is Oscillations and Waves, with 3 topics.

Are there flashcards for WBJEE Physics - Electromagnetism, Optics and Modern Physics?

Yes — a 50-card Physics - Electromagnetism, Optics and Modern Physics deck, printed in full in the flashcards section of this page and available in the Examius app with spaced repetition. The free plan covers one exam of your choice, including its flashcards; Examius Pro, a one-time purchase, unlocks every other exam and deck.