# Is potential difference is directly proptional to resistance?

Is potential difference is directly proptional to resistance? (atanu asks) Answer: For a constant current, the potential difference is directly proportional to the resistance included in the circuit. For a given conductor at constant temperature, resistance is a constant and the potential difference across it is directly proportional to the current passed through it.

# Electric Current and Conductor

I have a question based on current as we all know that current flows due to the movement of electrons in substance. Now suppose a conductor having electrons randomly in motion so we study that current flow due to flow of electrons in a substance so this have to produce electric current. Then why a … Continue reading Electric Current and Conductor

# Derive an expression for current in terms of drift velocity. (Derive I = nAev)

(This is being posted as per request from students) Consider a conductor of length l and area of cross section A. Let the number of free electrons per unit volume be n. When a pd V is applied, let the drift velocity of electrons be v. The total no. of free electrons in the piece … Continue reading Derive an expression for current in terms of drift velocity. (Derive I = nAev)

# what is the thermal conductivity of a perfect conductor?

Soumya asked: "What is the thermal conductivity of a perfect conductor?" Ans: Please check the link below for a detailed list of thermal conductivities of different materials. http://en.wikipedia.org/wiki/List_of_thermal_conductivities Every good conductor has some thermal conductivity - low or high. Just like superconductor, thermal conductivity may become infinity for a Thermal Superconductor. Thermal Superconductors may become a reality using CNT … Continue reading what is the thermal conductivity of a perfect conductor?

# SUSPENDED TYPE GALVANOMETER ANIMATION

A moving coil galvanometer is an instrument used for detection and measurement of small electric currents. Principle A current carrying conductor placed in a magnetic field experiences a torque. See Animation

# Noisy conductors shed light

A time-tested ...