Electrostatics Flashcards
What is electrostatics about? And what’s the equation?
It’s all about charges i.e. Coulomb’s law.
F = Kq * Q/ r^2
Here, q represents charges of two particles acting on each other and k (Coulomb’s constant - 9*10^9) and r (distance between two particles)
What’s the equation for electric field?
E= F/q I.e. force per charge
Here, F and q have a direct equivalent relationship where if we double the charge then we double the force one experiences. Hence, ratio of force per unit charge is constant at a point
What’s the equation for electric potential energy?
U = KQq/r
What’s voltage?
It’s the ratio of energy per unit charge. It depends on the charge and distance:
V = kQ/r
What’s reduction potential?
Measurement of energy per an amount of charge I.e voltage
What is true about the movement of electrons?
They always move from anode to cathode
Where is oxidation and reduction happening?
Oxidation (+) happens at the anode & while reduction (-) happens at the cathode
What’s the motion of electrons in galvanic cells?
From anode (- i.e. reduced) to cathode (+ i.e. oxidized)
It happens when battery is working i.e. giving charge away. Spontaneous
What’s the motion of electrons in electrolytic cells?
From cathode (- where reduction happens) to anode (+ where oxidation happens)
Battery is getting recharged i.e. non spontaneous since outside energy source is needed
What’s electromotive force?
Force that allows electrons to move through a pathway
What’s resistance in the flow of current?
The constraints that come in pathway I.e. they reduce the current
As the length of wire increases
the resistance of flow of e- increases I.e. the current decreases
However, larger cross sectional area means smaller resistance I.e. more current
What’s the equation for resistance?
R = p (L/A)
What’s required to measure the current (I)?
Electromotive force (Voltage) and resistance
I = V/R
What’s Ohm’s Law?
V = IR
What’s capacitance?
Amount of charge stored based on voltage applied
