Drift velocity and mobility
A small average drift speed can produce appreciable current because a metal contains many mobile electrons. Electron drift is opposite to conventional current.
Run this experiment →Physics · Class 12
Current Electricity
9 free physics experiments and lesson notes for Current Electricity, with model limits, worked examples and Tamil explanations.
Ohmic and non-linear VI curves
An ohmic element has a constant V/I ratio at fixed temperature. The illustrative filament model increases resistance with heating and bends the VI curve.
Run this experiment →Resistivity and temperature
Length and cross-section control resistance independently of the material resistivity. The linear temperature relation is valid over a limited range.
Run this experiment →Electrical power and Joule heating
The circuit converts electrical energy into heat. With fixed resistance, doubling voltage doubles current and quadruples power.
Run this experiment →Resistance combinations
Series elements carry the same current; parallel branches see the same voltage. The equivalent parallel resistance is below the smallest branch resistance.
Run this experiment →EMF and terminal voltage
EMF is energy supplied per unit charge inside the source. Internal resistance causes terminal voltage to drop when a load draws current.
Run this experiment →Series and parallel cells
Series cells raise EMF but also add internal resistance. Identical parallel cells retain one-cell EMF while reducing internal resistance. Compare small and large loads.
Run this experiment →Kirchhoff junction and loop rules
One series resistor feeds two parallel branches. Changing one branch changes the node voltage and both branch currents. The readout verifies charge conservation at the junction.
Run this experiment →Wheatstone and metre bridge
Find zero detector voltage in the bridge. A uniform metre wire turns a resistance ratio into a length ratio. Ratio arms in a post-office box use the same null principle.
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