Untitled Flashcards Set

THERMODYNAMICS - branch of physics that deals with the study of energy, heat, temperature

THERMAL ENERGY OR INTERNAL ENERGY (JOULES; J) 

• Total potential and kinetic energy of the molecules in the body

TEMPERATURE

• Average KInetic energy of individual molecules 

• hotness/coldness

• Measured by thermometer

UNITS OF TEMP 

• Kelvin (K) 

1. Named after William Thompson, 1st Baron Kelvin

• Celsius Temperature

2. Devised by Anders Celsius 

3. Based on the properties of water 

4. Formerly known as the centigrade scale

5. C= K - 273

6. C= 5/9 (F-32)

• Rankine Temperature 

1. Named after William John Macquorn Rankine 

2. Absolute scale of thermodynamic temp used in engineering systems.

3. R = 9/5 K

• Fahrenheit Temperature

1. Proposed by DANIEL GABRIEL FAHRENHEIT in 1724

2. F = R - 460

3. 9/5 C + 32

• Reaumur Temperature

1. Named after Rene Antoine Ferchault de Reaumur 

2. Freezing and boiling is 0 and 80

3. Re = 4/5C

KINDS OF THERMOMETER 

1. Liquid-in-a-tube thermometer = with temperature-sensitive liquid substance 

2. Gas-in-a tube thermometers = operates on basic volume constancy. Pressure increase, volume increase

3. Bimetallic Strip Thermometers = made by a pair of metals. 

THERMAL EQUILIBRIUM 

• All thermometers run on the basic principle of thermal equilibrium 

ZEROTH LAW OF THERMODYNAMICS

• If each two systems are in thermal equilibrium with another system, the other two systems are in thermal equilibrium also.

• The zeroth law can be restated by limiting thermal equilibrium in the context of equal temperature.

HEAT

CALORIMETRY 

• Science that deals with quantification of heat

• CALORIMETER, instrument used to measure heat

HEAT (Q)

• Amount of energy flowing from one body to another spontaneously due to their temperature difference 

• Form energy but energy in transit

• Joules (J), BTU (British Thermal Unit), Calories (Cal)

HEAT TRANSFER 

1. Conduction - molecule to molecule

2. Convection - moving of liquids and gasses in a circling current

3. Radiation - electromagnetic waves

Factors Affecting Heat 

1. Mass 

2. Change in temperature - greater change, greater the heat required

3. Specific Heat - amount of heat required to increase a temperature of material by unit temp. 

UNITS OF HEAT 

1. Calorie - amount of heat needed to change the temperature of 1g of water by 1C

2. KiloCalorie - 1kg of water by 1C

3. British Thermal Unit - 1lb of water by 1F

LAW OF HEAT EXCHANGE

• heat given up by a hotter body is equal to the heat absorbed by a colder body

• Heat lost = heat gained

THERMODYNAMIC LAWS

1. Zeroth Law 

• If two systems are in thermal equilibrium with a third system, they are in equilibrium with each other.

2. First Law: Energy cannot be created or destroyed, only transformed.

3. Second Law: Entropy (disorder) increases over time in an isolated system.

4. Third Law: Entropy approaches a constant as temperature nears absolute zero.

THERMAL EXPANSION

• Object expand when there is a change in temperature

1. Linear Expansion: Change in length due to temperature change.

2. Volume Expansion: Change in volume for liquids due to temperature change.

1. Introduction to Electricity:
   
   

   • Electricity arises from the presence or movement of charged particles.

   • Two branches:

     • Electrostatics: Stationary charges.

     • Electrodynamics: Flow of electrons through conductors.

2. Electric Charge:

• Fundamental property of matter 

• Matter is made of atoms with electrons (negative) and protons (positive).

• The unit of charge is Coulomb (C).

• Formula: q=neq = ne, where e=1.6×10−19Ce = 1.6 \times 10^{-19} C.

3. Conductors and Insulators:

   • Conductors: Allow electrons to flow freely (e.g., metals).

   • Insulators: Do not allow free flow of electrons (e.g., rubber).

   • Semiconductors: Intermediate behavior.

4. Charging Mechanisms:

   • Conduction: Direct contact transfer.

   • Friction: Rubbing objects together.

   • Induction: Charging without contact.

5. Law of Conservation of Charge:

   • Electric charge in a closed system remains constant.

6. Charge Interaction:

   • Opposite charges attract, like charges repel.

7. Electric Force (Coulomb's Law):

   • Electric force between two charges is directly proportional to the product of charges and inversely proportional to the square of the distance.

   • Formula:

8. F=kq1q2r2F = k \frac{q_1 q_2}{r^2}
   where k=8.99×109Nm2C2k = 8.99 \times 10^9 \frac{Nm^2}{C^2}.

Electric Field & Flux Summary Notes

Electric Field (N/C)

• A region where an electric force acts on a charged body.

• Formula: 

Electric Flux 

• Represents the number of electric field lines passing through a surface.

• Formula:  

Gauss’ Law of Electricity

• The total electric flux through a closed surface is equal to the net electric charge inside the surface.
  Formula:

Examples of Applications

• Electrocardiogram (ECG): Detects the heart's electric activity.

• Operating Room Equipment: Uses proper grounding to avoid electric shocks

Electric Potential Summary Notes

Electric Potential Energy

• energy of a charge in an electricfield, which gives its ability to do work.

Unit: Joule (J)

Formula:

Electric Potential (V)

• The electric potential energy per unit charge.

• Formula:

Potential Difference (∆V)

• Difference in electric potential between two points.

• Formula:

Work and Electric Potential

• Work is done when moving a charge between two points.

• Formula:

Equipotential Lines

• Lines where electric potential is constant.

• Always perpendicular to electric field lines.

Electron Volt (eV)

• Energy gained by an electron moving through 1 Volt.

• Conversion:

Electric Circuits

• Series Circuit: One pathway for electrons. If one component fails, the whole circuit stops.

• Parallel Circuit: Multiple pathways. If one component fails, others continue to work.

• Series-Parallel Circuit: Combination of series and parallel circuits.

Electric Circuit Symbols

.

Summary of Capacitance and Dielectrics Notes

1. Capacitor Overview

• A capacitor is a device that stores electric charge using two conductive plates separated by an insulating material.

• Difference from a battery:

  • Battery: Uses chemical reactions to move electrons.

  • Capacitor: Simply stores electrons without chemical reactions.

2. Capacitance

• Capacitance (C): The ability to store electric charge per unit voltage.

Formula:

3. Parallel-Plate Capacitor

Capacitance of a parallel-plate capacitor:

4. Dielectric Materials

• Dielectric: An insulating material placed between the plates to increase capacitance.

• Capacitance with dielectric:

Examples of Dielectric Constants:

• Air: 1.05

• Glass: 8.00

• Water: 80.4

5. Energy Stored in a Capacitor

The potential energy stored in a capacitor is given by:

6. Examples of Applications

• Camera flash units

• Defibrillators

• Energy storage in circuits

This summary highlights the main points and formulas for understanding capacitors and dielectrics.