Sudhanshi+Garg

= date- 13/03/2012  =

toc = =

Notes- difference between isothermal and adiabatic 1) Isothermal is a slow process whereas adiabatic is a fast process.   2) The graph of adiabatic is steeper than isothermal. 3) Isothermal means constant temperature whereas adiabatic means no in and out of energy.  4) during isothermal process the system is not insulated, (i.e.) the system must be in thermal equilibrium with its surrounding, whereas in adiabatic process the system is well insulated (i.e.) it is not in thermal equilibrium with its surrounding. = date- 27/03/2012 = R=(pl/a) where r- resistance p(roe)- resistivity l-length a- area construct your own quantitative approach about resistance https://docs.google.com/spreadsheet/ccc?key=0AhgfDczlEYk6dDdfMVV0LWFKMmZsdzlhdzJmeGdfTEE#gid=0 media type="custom" key="13541228" width="130" height="130" = date- 28/03/2012 = virtual dc lab- 1. when you have batteries in series, the voltage of each battery gets added. intensity depends voltage. when the batteries are in series the bulb gets maximum intensity. and the current is also directly proportional to the voltage. batteries in series 2. when the batteries are in parallel the voltage remains same, say i have connected two batteries of 9 volt each in parallel the total voltage across them would still be 9v. intensity is also less when batteries are connected in parallel and also the current decreases. batteries in parallel.
 * defination of resistance**- when current is passed through any body, the flow of charge experiences some hindrance, the hindrace provided by the material to the flow of charge is known as resistance. what is current- current is the rate of flow of charge. now if we look at a body with electrons and valence electrons, say copper. A copper wire, would consist of atoms, the last shell valence electrons come out of their shells now known as the free electrons would move here and there. now when current (electrons flow from the negative end to the positive end, they make space by taking the free electron with them to the positive electron but cant move the atom, which provide the resistance to the flow). when the temperature of the same solid increases, the atoms start vibrating at their places hence the resistance increases.

Factors affecting resistivity- 1. temperature 2. material

Factors affecting resistance- 1. length 2. crossectional area 3. Material 4. temperature 5. apart from these magnetic field, light intensity, electric field

ohms law- the law states that when factors affecting resistance like temperature, length and the cross sectional area and other factors, the voltage applied across the circuit is directly proportional to the current in the circuit. if the resistance in increased in the circuit the current decreases, and if the resistance decreases in the circuit the current increases to keep the product constant that is voltage. hence there is no effect of change in resistance to the voltage. resistace is the ratio of the voltage across the circuit to the current flowing in the circuit. v=ir, hence r=v/i. S.I unit- ohm.