Topics
Force, Work, Power and Energy
Force
Work, Power and Energy
- Introduction of Work
- Concept of Work
- Measurement of Work
- Work Done by the Force of Gravity (W = mgh)
- Power
- Concept of Energy
- Mechanical Energy and Its Types
- Potential Energy
- Types of Potential Energy
- Gravitational Potential Energy
- Kinetic Energy
- Types of Kinetic Energy
- Conversion of Potential Energy into Kinetic Energy
- Transformation of Energy
- Different Forms of Energy
- Principle of Conservation of Energy
- Theoretical verification of K + U = Constant for a freely falling body
- Application of Principle of Conservation of Energy to a Simple Pendulum
Machines
Light
Refraction of Light Through Plane Surface
- Refraction of Light
- Law of Refraction of Light
- Refractive Index
- Speed of Light
- Relationship Between Refractive Index and Speed of Light (µ = C/V)
- Principle of Reversibility of the Path of Light
- Experimental Verification of Law of Refraction
- Refraction of Light Through a Rectangular Glass Slab
- Multiple Images in a Thick Plane Glass Plate Or Thick Mirror
- Concept of Prism
- Refraction of Light Through a Prism
- Real and Apparent Depth
- Apparent Bending of a Stick Under Water
- Transmission of Light from a Denser Medium (Glass Or Water) to a Rarer Medium (Air) at Different Angles of Incidence
- Critical Angle
- Relationship Between the Critical Angle and the Refractive Index (µ = 1/ Sin C)
- Total Internal Reflection
- Total Internal Reflection in a Prism
Spectrum
- Deviation Produced by a Triangular Prism
- Colour in White Light with Their Wavelength and Frequency Range
- Concept of Prism
- Dispersion of Light Through Prism and Formation of Spectrum
- Electromagnetic Spectrum
- Different Radiation of Electromagnetic Spectrum
- Gamma Rays
- X rays
- Ultraviolet Radiations
- Visible Light
- Infrared Radiations
- Micro Waves
- Radio Waves
- Scattering of Light and Its Types
- Applications of Scattering of Light
Refraction of Light Through a Lense
- Lens
- Action of a Lens as a Set of Prisms
- Spherical Lens
- Refraction of Light Through the Equiconvex Lens and Equiconcave Lens
- Guideline for Image Formation Due to Refraction Through a Convex and Concave Lens
- Formation of Image by Reflection: Real and Virtual Image
- Images Formed by Sperical Lenses
- Concave Lens
- Images Formed Due to Refraction Through a Concave Lens
- Convex Lens
- Images Formed Due to Refraction Through a Convex Lens
- Differentiation Between Concave and Convex Lens
- Sign Convention for Spherical Lenses
- Lens Formula
- Magnification Due to Spherical Lenses
- Power of a Lens
- Magnifying Glass Or Simple Microscope
- Experimental Determination of Focal Length of Convex Lens
Sound
- Sound
- Difference Between the Sound and Light Waves
- Characteristics of a Sound Wave
- Reflection of Sound
- Echoes
- Natural Vibrations
- Damped Vibrations
- Forced Vibrations
- Resonance
- Demonstration of Resonance
- Properties of Sounds
- Loudness and Intensity
- Pitch (or shrillness) and frequency
- Audibility and Range
- Quality (Or Timbre) and Wave Form
- Noise Pollution
- Noise and Music
- Sound (Numerical)
Electricity and Magnetism
Current Electricity
- Electric Charge
- Electric Current
- Electric Circuit
- Potential and Potential Difference
- Resistance (R)
- Ohm's Law
- Experimental Verification of Ohm’s Law
- Ohmic and Non-ohmic Resistors
- Electrical Resistivity and Electrical Conductivity
- Choice of Material of a Wire
- Superconductors
- Electro-motive Force (E.M.F.) of a Cell
- Terminal Voltage of a Cell
- Internal Resistance of a Cell
- System of Resistors
- Resistors in Series
- Resistances in Parallel
- Series Connection of Parallel Resistors
- Parallel Connection of Series Resistors
Electrical Power and Energy and Household Circuits
- Electrical Energy
- Measurement of Electrical Energy (Expression W = QV = Vlt)
- Electrical Power
- Commercial Unit of Electrical Energy
- Power Rating of Appliances
- Household Consumption of Electric Energy
- Effects of Electric Current
- Heating Effect of Electric Current
- Transmission of Power from the Power Generating Station to the Consumer
- Household Electrical Circuits
- House Wiring (Ring System)
- Electric Fuse
- Miniature Circuit Breaker (MCB)
- Electric Switch
- Circuits with Dual Control Switches (Staircase Wire)
- Earthing (Grounding)
- Three-pin Plug and Socket
- Colour Coding of Live, Neutral, and Earth Wires
- High Tension Wires
- Precautions to Be Taken While Using Electricity
Electro Magnetism
- Effects of Electric Current
- Magnetic Effect of Electric Current
- Magnetic Field Due to a Current Carrying Straight Conductor
- Rule to Find the Direction of Magnetic Field
- Magnetic Field Due to Current in a Loop (Or Circular Coil)
- Magnetic Field Due to a Current Carving Cylindrical Coil (or Solenoid)
- Electromagnet
- Making of an Electromagnet
- Permanent Magnet and Electromagnet
- Applications of Electromagnets
- Force on a Current Carrying Conductor in a Magnetic Field
- Direct Current Motor
- Electromagnetic Induction
- Faraday's Laws of Electromagnetic Induction
- Alternating Current (A.C.) Generator
- Distinction Between an A.C. Generator and D.C. Motor
- Types of current: Alternating Current (A.C.) and Direct Current (D.C.)
- Transformer
- Types of Transformer
Heat
- Heat and Its Unit
- Temperatures
- Heat and Temperature
- Heat Capacity Or Thermal Capacity
- Specific Heat Capacity
- Relationship Between the Heat Capacity and Specfic Heat Capacity
- Calorimetry and Calorimeter
- Natural Phenomena and Consequences of High Specific Heat Capacity of Water
- Some Examples of High and Low Heat Capacity
- Change of State of Matter
- Concept of Melting (Fusion)
- Concept of Freezing (Solidification)
- Concept of Boiling (Vaporization)
- Concept of Condensation (Liquefaction)
- Latent Heat and Specific Latent Heat
- Specific Latent Heat of Fusion of Ice
- Explanation of Latent Heat of Melting on the Basis of Kinetic Model
Modern Physics
- Atoms: Building Blocks of Matter
- Structure of an Atom
- Discovery of Charged Particles in Matter
- Nucleus
- Atomic Mass
- Atomic Number (Z), Mass Number (A), and Number of Neutrons (n)
- Isotopes
- Isobars
- Isotones or Isoneutronic
- Radioactivity
- Radioactivity as Emission of Alpha, Beta, and Gamma Radiations
- Properties of Alpha Particles
- Properties of Beta Particles
- Properties of Gamma Radiations
- Changes Within the Nucleus in Alpha, Beta and Gamma Emission
- Alpha Decay (Alpha Emission)
- Beta Decay (Beta Emission)
- Gamma Decay (Gamma Emission)
- Uses of Radioactive Isotopes
- Radiation
- Nuclear Energy
- Safety Precautions While Using Nuclear Energy
- Nuclear Fission
- Nuclear Fusion
- Distinction Between the Radioactive Decay and Nuclear Fission
- Distinction Between the Nuclear Fission and Nuclear Fusion
description
- Definition of power
- Unit of power
- Relation between power and velocity
notes
Power
-
Power is defined as the time rate at which work is done or energy is transferred.
Average Power:
Ratio of work done(W) in a total time interval of t.
`P_(av)`= `W/t`
Instantaneous Power:
When the time interval t, approaches zero the limiting value of average power becomes instantaneous power.
`P = (dW)/dt`
-
We can write `W = F. dr,`
`P = F . (dr)/dt`
`P = F.v` , where v is instantaneous velocity. -
Power is a scalar quantity
-
SI unit of power – Watt (W)
-
Its dimensions are [ML2T–3].
-
1 hp = 746 W
-
We encounter the unit watt when we buy electrical goods such as bulbs, heaters and refrigerators. A 100 watt bulb which is on for 10 hours uses 1 kilowatt hour (kWh) of energy.
100 (watt) × 10 (hour) = 1000 watt hour
= 1 kilowatt hour (kWh)
= 103 (W) × 3600 (s)
= 3.6 × 106 J
-
Our electricity bills carry the energy consumption in units of kWh. Note that kWh is a unit of energy and not of power.
Example: A pump on the ground floor of a building can pump up water to fill a tank of volume 30 m3 in 15 min. If the tank is 40 m above the ground, and the efficiency of the pump is 30%, how much electric power is consumed by the pump?
Solution: `P = W/t = (mgh)/t`
mass of water to be moved = ρV = 30000 kg
g = 9.8
h = 40 m
t = 15 x 60 = 900 s
P = 13066.67 W = 13.067 kW
Now `η = P/(P_(ACTUAL)) => P_(ACTUAL) = 13.067/0.3 = 43.6 kW`