Derive I = nAVe
Over 1 second, electrons with drift velocity V travel through a wire of cross sectional area A. Distance Vt (t = 1) multiplied by area A gives a volume AV. This volume multiplied by the electron density of the material n, gives the number of electrons in volume V, nAV. The charge in the volume of material is found by multiplying the number of electrons by the elementary charge e, nAVe. This is the amount of charge passing through the wire every second, or current I. Therefore, I = nAVe
DD
Related Physics A Level answers
All answers ▸why does photoelectric emission occur only when there is a certain threshold frequency of incident radiation?
What does the double slit experiment tell us about light?
A projectile is launched from ground level with a speed of 25 m/s at an angle of 42° to the horizontal. What is the horizontal distance from the starting point of the projectile when it hits the ground?
An infared wave has a wavelength of 1.5 x10^–6 m. The speed of this wave is 2.2 × 10^8 m/s. Calculate the frequency of the wave. Give your answer in standard form and to 2 significant figures.