# Physics HL & SL: Definitions:Topics 5 and 6 - Electric Currents & Fields and Forces

## 15 terms · IB Physics Definitions and Statements as in IB Syllabus.

### Electric Potential difference

Work done per unit charge to move a small positive charge between two points

### The Electron Volt

Work done in moving an electron through a potential difference of one volt

### Electric Current

Force per unit length between parallel current-carrying conductors

R = V / I

### Ohm's law

Current is proportional to voltage at constant temperature for ohmic resistors

### Electromotive Force (emf)

Total electrical energy supplied by the cell per unit charge as it flows through the cell

### Newton's Universal law of gravitation

The force between two spherical masses whose separation is large compared to their radii is the same as if the two spheres were point masses with their masses concentrated at the centres of the spheres

### Gravitational Field Strength

The force per unit mass placed at that point

+/-

### The Law of conservation of charge

The total energy of a closed system is constant

### Coulomb's law

F = k (q1)(q2) /r^2

### Electric Field Strength

The force per unit charge felt by a positive test charge placed in the field

### State: Moving charges give rise to magnetic fields

e.g. Moving charge/current in a wire creates a magnetic field around the wire

B = F / I L sinθ

From N to S