physics laws and definitions Flashcards
what is Kirchhoff’s first law?
total current entering a junction=total current leaving it
what is Kirchhoff’s second law?
total e.m.f around a series circuit= sum of p.d.s across each component
what is Lenz’s law?
The direction of the induced emf is always in such a direction as to oppose the change that caused it
what is Faraday’s law?
induced emf is directly proportional to the rate of change of flux linkage
Define the electric field strength at a point in an electric field
- is the force per unit charge
- On a (small) positive charge (at that point)
State what is represented by gravitational field lines
- ## Gravitational field lines show the direction of force on a mass
Define the gravitational potential at a point.
- the work done per unit mass
- in moving from infinity to the point
Define gravitational field strength and state whether it is a scalar or vector quantity.
- force per unit mass
- a vector quantity
what is Coulomb’s law?
f=q1q2
4piEr^2
gives the force of attraction or repulsion between two point charges
what is Boyle’s law?
at constant temperature, pressure and volume are inversely proportional
what is Charles’ law?
at constant pressure volume is directly proportional to temperature
what is the pressure law?
at constant volume the pressure is directly proportional to the temperature
what is flux linkage?
a magnetic field going through a coil of wire equal to the flux times the number of coils in the wire
what is angular velocity?
rate of change of angular displacement with respect to time swept out by the radius
