Question

$\mathbb{ \underline{ \large{CURRENT \: \: ELECTRICITY }}}$

1) What is drift velocity ?

2) What are the limitations of ohm's law ?

3) Explain Kirchhoff's rules
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Answer 1

Question 1 :-

What is drift velocity ?

→ Drift velocity is the average velocity attained by charged particles, such as electrons, in a material due to an electric field.

Question 2 :-

What are the limitations of ohm's law ?

→ The limitations of ohm's law :-

• This law cannot be applied to unilateral networks, which do not have same voltage current relation for both directions of current.
• Ohm's law is also not applicable for non – linear elements.

Question 3 :-

Explain Kirchhoff's rules

→ Kirchhoff's first rule—the junction rule. The sum of all currents entering a junction must equal the sum of all currents leaving the junction. Kirchhoff's second rule—the loop rule. The algebraic sum of changes in potential around any closed circuit path (loop) must be zero.

Answer 2

Answer:

$\red{ \sf{ \bold{ \huge{Drift \: Velocity}}}}$

Drift Velocity is the Average Velocity attained by charge carrying particles (like Electrons) while drifting from the negative terminal to the positive terminal of a conductor.Whenever, a conductor is attached to a potential difference, the electrons start moving from the negative towards the positive terminal.During that motion, the electrons are said to be drifting. Drifting actually signifies a zig-zag type of motion (ultimately causing a displacement).Drift Velocity is dependent on many factors :CurrentElectron densityCross section of Conductor.

$\red{ \sf{ \large{Limitations \: of \: Ohms \: Law}}}$

Ohms law is not applicable once the physical parameters pf environment change ( eg temperature)Not applicable for Semi-conductors like Diodes or Transistors.

$\red{ \sf{ \large{Kirchoff's \: Law}}}$

For 1st law , It says that current at any junction is zero. This is because there is no accumulation of charges at any junction.Incoming Current = Outgoing CurrentFor 2nd Law, it says that the total Potential Difference in a loop is zero.This is because , when we start from a particular point in the loop and end at that point , the potential remains same. Hence the difference of Potential becomes zero.