Electricity & Magnetism


Comments

Post a Comment

Popular posts from this blog

Grade thresholds

PHYSICS GCE Advanced Level and GCE Advanced Subsidiary Level Grade thresholds taken for Syllabus 9702 (Physics) in the May/June 2011 examination. The thresholds (minimum marks) for Grades C and D are normally set by dividing the mark range between the B and the E thresholds into three. For example, if the difference between the B and the E threshold is 24 marks, the C threshold is set 8 marks below the B threshold and the D threshold is set another 8 marks down. If dividing the interval by three results in a fraction of a mark, then the threshold is normally rounded down. Grade A* does not exist at the level of an individual component. The thresholds for the syllabus are determined first by adding together the thresholds for the components taken by the candidate. A reduction may be made at the higher grades depending on the correlation of the papers. If the maximum raw marks for the components are not in the weighting/relationship specified in the syllabus, a weighting is applied...
Read more

Thermal Physics

Thermal Physics Internal Energy:  is the sum of the kinetic energy of the molecules  due to its random motion  & the potential energy of the molecules due to the intermolecular forces. Internal energy is  determined by the values of the current state  and is  independent of how the state is arrived at . Thus if a system undergoes a series of changes from one state A to another state B, its change in internal energy is the same, regardless of which path {the changes in the p & V} it has taken to get from A to B. Since Kinetic Energy proportional to temp, and internal energy of the system = sum of its Kinetic Energy and Potential Energy, a rise in temperature will cause a rise in Kinetic Energy and thus an increase in internal energy. If two bodies are in  thermal equilibrium , there is  no  net  flow of heat energy between them  and they have the  same temperature . {NB: this  does not imply they must hav...
Read more