"Electrons move at the speed of light in a wire." FALSE. Drift velocity is ~10^{-4} m/s. The electric field signal propagates at ~c, not the electrons themselves.

"More current means electrons move faster overall." PARTIALLY TRUE for vd, but random thermal speed (~10^{5} m/s) is unaffected by current.

"A potentiometer measures terminal voltage like a voltmeter." FALSE. At the null point, no current flows from the test cell. Potentiometer measures TRUE EMF.

"Resistivity depends on the length and area of the conductor." FALSE. Resistivity is a material property, independent of geometry. Resistance depends on geometry; resistivity does not.

"All materials obey Ohm's law." FALSE. Only ohmic conductors have constant R. Diodes, filament bulbs at varying temperatures, and electrolytes are non-ohmic.

"A short circuit has very high resistance." FALSE. Short circuit means R → 0, leading to very high current I = ε/r.

"Terminal voltage equals EMF always." FALSE. V = ε only when I = 0 (open circuit). When current flows, V = ε − Ir < ε.

"Semiconductor resistance increases with temperature like metals." FALSE. Semiconductors have negative α — resistance decreases with temperature.

"In series circuit, the component with most resistance has most voltage but least current." HALF TRUE. Most voltage: yes (V = IR, same I). Least current: NO — series has the SAME current through all components.

"In parallel, the component with most resistance carries most current." FALSE. Parallel: same voltage → I = V/R; largest R carries LEAST current.

"Interchanging battery and galvanometer in a balanced Wheatstone bridge unbalances it." FALSE. The reciprocity theorem guarantees balance is maintained.

"Balance length in potentiometer is always 50 cm." FALSE. Balance length depends on the EMF of the test cell and the potential gradient. It can be anywhere from 0 to 100 cm (preferably in the middle range for accuracy).

"The metre bridge is more accurate than the Wheatstone bridge." FALSE. Accuracy depends on the sensitivity of the galvanometer and the precision of resistances, not the instrument type. Both are null methods with similar precision.

"Power always increases when resistance increases." FALSE. It depends on what is held constant. For constant I: P = $I^{2}$R increases with R. For constant V: P = $V^{2}$/R decreases with R.

"Internal resistance of a cell is zero." FALSE. All real cells have some internal resistance r. Higher r → more voltage wasted internally → lower terminal voltage under load.

"The colour code of a resistor gives exact resistance." FALSE. The fourth band (tolerance) means the actual resistance is within ±5% (gold), ±10% (silver), or ±20% (none) of the marked value.

"Current density and current are the same." FALSE. J = I/A is current per unit area. A thick wire carrying 1 A has lower J than a thin wire carrying the same current.