Current Electricity

Answer

Electric current is the rate of flow of electric charge. It is defined as i = Q/t, where Q is charge and t is time. The SI unit of current is ampere (A). 1 ampere is the current that flows when 1 coul

Answer

When i = 1 ampere and t = 1 second, the number of electrons n = 6.25 × 10^18 electrons. This is calculated using i = net, where e = 1.6 × 10^-19 coulomb (charge of one electron).

Answer

Electric potential is the work done in bringing unit positive charge from infinity to a point. V = W/Q. Potential difference is the work done in moving unit positive charge from one point to another.

Answer

Electric resistance is the obstruction offered to the flow of current through a conductor. It is caused by collisions between free electrons and positive ions in the metallic conductor. Due to these c

Answer

The four factors are: 1) Nature of conductor (different materials have different free electron concentrations), 2) Length of conductor (R ∝ l), 3) Area of cross-section (R ∝ 1/A), 4) Temperature of co

Answer

Ohm's Law states that the current flowing through a conductor is directly proportional to the potential difference across its ends, provided physical conditions remain constant. Mathematically: V = iR

Answer

The SI unit of resistance is ohm (Ω). R = V/i = volt/ampere = ohm. Higher units are: kilo-ohm (kΩ) = 1000Ω and mega-ohm (MΩ) = 10^6Ω. Conductance is the reciprocal of resistance: σ = 1/R, measured in

Answer

Ohm's Law has the following limitations: 1) Physical conditions must remain constant, 2) Temperature should be constant, 3) It applies only to ohmic conductors (linear resistors), 4) It does not apply