Thermodynamics
Zero Law of thermodynamics: If two bodies A and B are separately in equilibrium with a Body C; then A and B will be in equilibrium with each other.
First Law of thermodynamics: The amount of heat given to the system is used in two ways to increase the temperature of the body and to the external work.
Second Law of thermodynamics: The entropy of system can only increase over time.
Thermal Expansion
The tendency of matter to change in shape, area, and volume in response to the change in temperature.
Practical application of thermal expansion:
HEAT TRANSFER
Zero Law of thermodynamics: If two bodies A and B are separately in equilibrium with a Body C; then A and B will be in equilibrium with each other.
First Law of thermodynamics: The amount of heat given to the system is used in two ways to increase the temperature of the body and to the external work.
Second Law of thermodynamics: The entropy of system can only increase over time.
Thermal Expansion
The tendency of matter to change in shape, area, and volume in response to the change in temperature.
Practical application of thermal expansion:
- A gap is given in telephone wire to allow the wires contract in winter.
- In summer the pendulum clock run slower, because length of the pendulum increase in summer.
- Iron rails of railway track are provided with a gap, so that the rail can easily expand in Summer and thus will not bend.
HEAT TRANSFER
CONDUCTION
CONVECTION
- Heat is transferred by the actual movement of particle medium.
- In liquid and gas convention takes place in solid.
RADIATION
- Quickest way to transfer heat. As no material medium is required.
- Heat from sun enters the atmosphere of the Earth by radiation.
- Heat is transferred without actual movement of particle
- Conduction take place in solid.CONVECTION
- Heat is transferred by the actual movement of particle medium.
- In liquid and gas convention takes place in solid.
RADIATION
- Quickest way to transfer heat. As no material medium is required.
- Heat from sun enters the atmosphere of the Earth by radiation.
SIMPLE HARMONIC MOTION
If a body moves to and fro on a straight line about fixed position, then its motion is called S.H.M.
When a particle execute SHM, then on its mean position: -no force acts on it, its velocity is maximum, KE is maximum, potential energy is zero.
When body is at extreme position
Velocity particle is zero, acceleration is maximum, kinetic energy of particle is zero, restoring force is maximum.
SIMPLE PENDULUM
- A heavy point mass suspended from a rigid support by means of an elastic string.
- The maximum time period of a simple pendulum is 84.6 min.
- A pendulum clock goes slower in summer and faster in winter.
- At moon, time period of simple pendulum is increases, because acceleration due to gravity at Moon decreases.
WAVE MOTION
Wave are of two types: Mechanical and Electromagnetic.
A. Mechanical Wave : These require medium for their transportation. There are further divided in two types.
I. Longitudinal Wave: In this particle of medium vibrate in the direction of propagation of wave. E.g Sound wave in air.
II. Transverse wave: In this particle vibrate perpendicular to the direction of propagation of wave. E.g. Waves on the surface of the water.
B. Electromagnetic Wave: They do not require any material medium for their propagation i.e. they even propagate through vacuum. They propagate as transverse wave. E.g. Light
ELECTRICITY AND MAGNETISM
CHARGE
Charge is basic property associated with matter due to which it produces and experiences electrical and magnetic effects. Similar charges repel each other and opposite charges attract each other. The SI unit of charge is COULOMB.
CONDUCTOR
Conductor are those materials, which allow electricity to pass through them. Metal like silver, iron, copper and earth act as conductor.Silver is the best conductor.
INSULATOR
Insulator are those materials which do not allow electricity to flow through them. Metal like wood, paper, mica, glass, are insulator.
ELECTRIC CURRENT
Its unit is Ampere. It is a scalar quantity.
An electric bulb makes a bang when it is broken because there is vacuum inside the electric bulb, when bulb is broken air rushes at great speed from all side to fill the vacuum. The rushing of air produces a noise generally referred to as the bang.
ELECTRIC CELL
Primary Cell
|
Secondary Cell
|
|---|---|
| Energy is obtained from irreversible chemical reaction. | Rechargeable storage battery. |
| After getting completely discharge they can not recharged with electricity and reused. | Energy is obtained by reversible chemical reactions. |
| E.g. Voltaic cell, Lelanche cell, Dry cell, Daniel Cell | E.g. Lead storage battery, cadmium storage cell. |
TRANSFORMER
- A device used to transfer electrical energy from one circuit to another. With an alternating current, a transfer will raise (Step up) or lower (Step down) lower the voltage.
- Based on electromagnetic induction (Faraday's law)
AMMETER
- It is used to measure electric current.
- It is always connected in series.
- The resistance of ideal ammeter is zero.
VOLTMETER
- It is used to measure the potential difference between the two point of an electric circuit.
- It is always connected in parallel.
- The resistance of ideal voltmeter is infinite.
GALVANOMETER
- It is used to detect the presence of current in circuit.
- In order to convert galvanometer into voltmeter a very high resistance known as "series resistance" is connected in series with galvanometer.
- In order to convert galvanometer to ammeter a shunt resister is connected in parallel to galvanometer.