Physics Syllabus | Bsc-csit Entrance

PHYSICS NOTES

Physics tests conceptual understanding and problem-solving ability in real-world scenarios.

MECHANICS

1. DIMENSION, ERROR ANALYSIS AND VECTOR

Physical Quantity

A measurable quantity is called a physical quantity.

Fundamental Quantities

Quantity	Symbol	SI Unit
Length	$L$	meter
Mass	$M$	kilogram
Time	$T$	second

Dimensional Formula

Velocity

$$ [v]=[LT^{-1}] $$

Force

$$ [F]=[MLT^{-2}] $$

Energy

$$ [E]=[ML^2T^{-2}] $$

Error Analysis

Absolute Error

$$ \Delta a = |a_{measured}-a_{true}| $$

Percentage Error

$$ %\text{ Error} = \frac{\Delta a}{a}\times100 $$

Vector

A quantity having both magnitude and direction.

Magnitude of Vector

For vector:

$$ \vec A = A_x\hat i + A_y\hat j $$

Magnitude is:

$$ |A|=\sqrt{A_x^2+A_y^2} $$

Dot Product

$$ \vec A\cdot\vec B = AB\cos\theta $$

Cross Product

$$ \vec A\times\vec B = AB\sin\theta $$

2. KINEMATICS, NEWTON'S LAWS AND FRICTION

Speed

$$ \text{Speed}=\frac{\text{Distance}}{\text{Time}} $$

Velocity

$$ \text{Velocity}=\frac{\text{Displacement}}{\text{Time}} $$

Acceleration

$$ a=\frac{v-u}{t} $$

Equations of Motion

$$ v=u+at $$

$$ s=ut+\frac{1}{2}at^2 $$

$$ v^2=u^2+2as $$

Newton's First Law

A body remains at rest or in uniform motion unless acted upon by external force.

Newton's Second Law

$$ F=ma $$

Newton's Third Law

For every action there is an equal and opposite reaction.

Frictional Force

$$ F=\mu N $$

where:

$$ \mu = \text{coefficient of friction} $$

3. WORK, ENERGY, POWER AND COLLISION

Work Done

$$ W=Fs\cos\theta $$

Kinetic Energy

$$ KE=\frac{1}{2}mv^2 $$

Potential Energy

$$ PE=mgh $$

Power

$$ P=\frac{W}{t} $$

Conservation of Energy

Energy can neither be created nor destroyed.

Momentum

$$ p=mv $$

Impulse

$$ J=Ft $$

Conservation of Momentum

$$ m_1u_1+m_2u_2=m_1v_1+m_2v_2 $$

4. CIRCULAR MOTION AND GRAVITATION

Centripetal Force

$$ F=\frac{mv^2}{r} $$

Angular Velocity

$$ \omega=\frac{v}{r} $$

Newton's Law of Gravitation

$$ F=G\frac{m_1m_2}{r^2} $$

Gravitational Potential Energy

$$ U=-G\frac{Mm}{r} $$

Escape Velocity

$$ v_e=\sqrt{\frac{2GM}{R}} $$

5. ROTATIONAL MOTION

Angular Displacement

$$ \theta=\frac{s}{r} $$

Torque

$$ \tau=rF\sin\theta $$

Moment of Inertia

$$ I=\sum mr^2 $$

Rotational Kinetic Energy

$$ KE=\frac{1}{2}I\omega^2 $$

Angular Momentum

$$ L=I\omega $$

6. SHM, HYDROSTATICS, SURFACE TENSION, FLUID DYNAMICS, ELASTICITY

Simple Harmonic Motion

Equation

$$ x=A\sin\omega t $$

Time Period

$$ T=\frac{2\pi}{\omega} $$

Hooke's Law

$$ F=-kx $$

Pressure in Liquid

$$ P=h\rho g $$

Pascal's Law

Pressure applied to enclosed fluid is transmitted equally.

Surface Tension

$$ T=\frac{F}{l} $$

Bernoulli's Equation

$$ P+\frac{1}{2}\rho v^2+\rho gh=\text{constant} $$

Young's Modulus

$$ Y=\frac{\text{Stress}}{\text{Strain}} $$

HEAT AND THERMODYNAMICS

7. THERMOMETRY AND THERMAL EXPANSION

Temperature Conversion

$$ \frac{C}{5}=\frac{F-32}{9}=\frac{K-273}{5} $$

Linear Expansion

$$ \Delta L=\alpha L_0\Delta T $$

Volume Expansion

$$ \Delta V=\gamma V_0\Delta T $$

8. CALORIMETRY, CHANGE OF STATE, HYGROMETRY

Heat Equation

$$ Q=mc\Delta T $$

Latent Heat

$$ Q=mL $$

Specific Heat Capacity

$$ c=\frac{Q}{m\Delta T} $$

Relative Humidity

$$ RH=\frac{\text{Actual Vapor Pressure}}{\text{Saturation Vapor Pressure}}\times100 $$

9. KINETIC THEORY, GAS LAWS, THERMODYNAMICS

Ideal Gas Equation

$$ PV=nRT $$

Boyle's Law

$$ PV=\text{constant} $$

Charles's Law

$$ \frac{V}{T}=\text{constant} $$

First Law of Thermodynamics

$$ \Delta Q=\Delta U+\Delta W $$

Efficiency of Heat Engine

$$ \eta=\frac{W}{Q_h}\times100 $$

10. TRANSMISSION OF HEAT

Conduction

Transfer of heat through direct contact.

Convection

Transfer of heat through fluid motion.

Radiation

Transfer of heat without medium.

Stefan-Boltzmann Law

$$ E=\sigma T^4 $$

OPTICS

11. REFLECTION AND REFRACTION (MIRROR, LENS, PRISM)

Mirror Formula

$$ \frac{1}{f}=\frac{1}{v}+\frac{1}{u} $$

Magnification

$$ m=\frac{v}{u} $$

Lens Formula

$$ \frac{1}{f}=\frac{1}{v}-\frac{1}{u} $$

Refractive Index

$$ \mu=\frac{\sin i}{\sin r} $$

Prism Formula

$$ \delta=(\mu-1)A $$

12. TOTAL INTERNAL REFLECTION, DISPERSION OF LIGHT

Condition for Total Internal Reflection

$$ i>C $$

where:

$$ C=\text{critical angle} $$

Critical Angle

$$ \sin C=\frac{1}{\mu} $$

Dispersion

Splitting of white light into colors.

13. PHOTOMETRY AND OPTICAL INSTRUMENTS

Luminous Intensity

Measured in candela.

Illuminance

$$ E=\frac{I}{r^2} $$

Magnifying Power

$$ M=\frac{D}{f} $$

WAVE

14. WAVE MOTION, VELOCITY OF SOUND

Wave Equation

$$ v=f\lambda $$

Frequency

$$ f=\frac{1}{T} $$

Velocity of Sound

$$ v=\sqrt{\frac{\gamma P}{\rho}} $$

15. STATIONARY WAVES, DOPPLER'S EFFECT

Stationary Wave

Produced by superposition of two waves.

Doppler Effect

Apparent change in frequency due to relative motion.

Doppler Formula

$$ f'=f\left(\frac{v\pm v_o}{v\mp v_s}\right) $$

16. INTERFERENCE, DIFFRACTION, POLARIZATION

Interference

Superposition of light waves.

Young's Double Slit Formula

$$ \beta=\frac{\lambda D}{d} $$

Diffraction

Bending of light around obstacle.

Polarization

Restriction of vibration in one plane.

ELECTRICITY AND MAGNETISM

17. ELECTRIC CURRENT, CAPACITORS, HEATING EFFECTS

Electric Current

$$ I=\frac{Q}{t} $$

Ohm's Law

$$ V=IR $$

Electric Power

$$ P=VI $$

Joule's Law

$$ H=I^2Rt $$

Capacitance

$$ C=\frac{Q}{V} $$

Energy Stored in Capacitor

$$ U=\frac{1}{2}CV^2 $$

18. MAGNETISM, ELECTROMAGNETIC INDUCTION, ALTERNATING CURRENT

Magnetic Force

$$ F=qvB\sin\theta $$

Force on Current Carrying Wire

$$ F=BIL\sin\theta $$

Faraday's Law

$$ E=-\frac{d\phi}{dt} $$

Alternating Current

$$ I=I_0\sin\omega t $$

RMS Value

$$ I_{rms}=\frac{I_0}{\sqrt2} $$

MODERN PHYSICS

19. CHARGED PARTICLES, PHOTOELECTRIC EFFECT, ATOMIC STRUCTURE

Coulomb's Law

$$ F=k\frac{q_1q_2}{r^2} $$

Photoelectric Equation

$$ h\nu=\phi+KE $$

Bohr Radius

$$ r_n=n^2a_0 $$

Energy of Electron

$$ E_n=-\frac{13.6}{n^2}\text{ eV} $$

20. X-RAYS, NUCLEAR PHYSICS, SEMICONDUCTORS

Radioactive Decay Law

$$ N=N_0e^{-\lambda t} $$

Half Life

$$ T_{1/2}=\frac{0.693}{\lambda} $$

Mass-Energy Relation

$$ E=mc^2 $$

Binding Energy

$$ BE=\Delta mc^2 $$

Semiconductor

A material with conductivity between conductor and insulator.

Diode

Allows current in one direction.

Transistor

Used for amplification and switching.

IMPORTANT FORMULAS SUMMARY