Physics A Level Aqa Study Guide Rated A+

vector {Ans: physical quantity with magnitude and direction}electric potential {Ans: work done per unit charge on a small positively charged object to move it from infinity to that point in the field - potential at infinity is 0}matter waves {Ans: wave-like behaviour of particles}renewable energy {Ans: energy from a source that is continually renewed, eg: hydroelectricity tidal power geothermal power solar power wave power wind power}diffraction grating {Ans: plate with close parallel slits on it}Lenz's Law {Ans: when a current is induced by electromagnetic induction the direction of the induced current is always such as to oppose the change that causes the current}stress {Ans: force per unit area of cross section in a solid perpendicular to cross section}Ohm's Law {Ans: PD across a metallic conductor is proportional to the current - if physical conditions remain constant}resonance {Ans: amplitude of vibration of an oscillating system subjected to a periodic force is largest when the periodic force has the same frequency as the resonant frequency of the system for lightly damped system - periodic force = natural frequency at resonance the system vibrates such that its velocity is in phase with the periodic