CLASS 8 · LEARNING KNOWLEDGE
Electrical resistance and Ohm's law – basic principles
How it works
Ohm's law describes the relationship between voltage (U), current (I) and electrical resistance (R) for ohmic resistors: U = R·I. The resistance of a conductor is a measure of how strongly it impedes the electric current. The unit of resistance is ohm (Ω). Different materials, the length, the cross-section and the temperature influence the resistance. Ohm's law applies only to ohmic resistors, in which voltage and current are proportional to each other.
Note
The electrical resistance of an ohmic resistor is calculated using Ohm's law: R = U/I, where U is the voltage in volts and I is the current in amperes.
The electrical resistance of an ohmic resistor is calculated using Ohm's law: R = U/I, where U is the voltage in volts and I is the current in amperes.
An example
An ohmic resistor is connected to a voltage of 12 V. A current of 2 A flows. How large is the resistance?
R = U/I = 12 V / 2 A = 6 Ω. The resistance is 6 ohm.
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50 Exercises
To the learning unit →Own explanation and own practice exercises by AmyMath. Subject reference framework: Physics. The topic assignment may vary by federal state.