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## What is pseudo force

What is pseudo force when it is applied ?

Pseudo force is also called fictitious force.

A fictitious force arises when a frame of reference is accelerating compared to a non-accelerating frame.

For example if you consider a person standing at a bus stop watching an accelerating car, he infers that a force is exerted on the car and it is accelerating. Here there is no problem and the pseudoforce concept is not required

But, if the person inside the accelerating car is looking at the person standing at the bus stop, he finds (more…)

## Current Carriers and conduction

1. Do the protons flow when current flow?
2. In case of semiconductor do the holes flow?

In metallic conductors, free electrons are the current carriers, i.e, it is due to the motion of the free electrons that conduction takes place in a metallic conductor. The protons do not move as they are inside the nucleus and bound by strong nuclear forces. It is the electrons of the outermost shell of the atom which are least bound to the atom, flow and cause conduction

In semiconductors the current carriers are free electrons and holes.

What are holes?

Holes are actually vacancies created when an electron is freed from a bond. It is assigned a positive charge. When a potential difference is applied across a semiconductor, the free electrons move towards the positive terminal as in the case of a metal. The bonded electrons also move towards positive terminal from vacancy to vacancy and this causes the holes  t move towards the negative terminal.

## Discuss the Difficult questions of AISSCE 2012

How was the Physics Question Paper for AISSCE (CBSE Class 12) 2012?

Many students complained that many questions of Physics question paper AISSCE 2012 were unexpected and hard.

Do you think so?

Post the questions you felt hard or unexpected here as comment to this post. Let us discuss them here.

## Physics Sample Papers for AISSCE (CBSE Class XII)

You can find more than 50 Sample Papers at http://physics.2lv.in

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