Home » 2013 » March (Page 2)

# Monthly Archives: March 2013

## How was your AISSCE Class 12 Physics Exam 2013?

How was your AISSCE Class 12 Physics Exam 2013?

Many students reported that the questions were extra ordinarily tough. What was your experience?

Use the comment form below to tell us the problems you found in Physics question paper.
Chirag says:
“equipotential surfaces! question no. 29,

draw the equipotential surface for two dipoles. I drew the equipotential plane for the two dipoles! will I be awarded points for this?
Question Paper series: 2   Outside Delhi”

Alaap Says:
What problems did you find: It was pretty good.The question number 20 was something i din’t know.The last question on the graph of flux and emf versus (omega t) was direct but i messed it up. And the paper was quite lengthy.If i had the time i would not have panicked and would have been able to do the graphs. And the rest here and there one mark or half mark questions.So i was a bit worried but my sister told that i might get 60+/70.Hope that comes true! Scared! *Fingers Crossed*

## Must Practice portions for class xi physics

Hi Class XI Students!

The following portions are very much essential for obtaining a pass mark in class XI. So please read the portions from your text book well and try to answer the questions which can be asked from them.

• Uses of dimensional analysis
• Types of errors and propagation off errors
• derivation of equations of uniformly accelerated motion graphically.
• Derive expression for the trajectory of a projectile (or show that the trajectory of a projectile is a parabola.
• Derive expression for the horizontal range, time of flight and max. height of a projectile motion
• Derive expression for centripetal acceleration of a body in uniform circular motion.
• State the laws of motion
• Derive F = ma (more…)

## Working Principle of Van de Graff generator

What is the working principle of Van de Graff generator?

There are basically two principles involved. The principle stresses in NCERT text book is that,

If we consider two concentric spheres connected electrically, then any charge given to the inner conductor will immediately be transferred to the outer sphere, irrespective of the amount of charge already present on the outer sphere. This happens because, the inner sphere is always at a higher potential and charges flow from high potential to low potential.

Another principle involved is the action of sharp points and corona discharge.

When a conductor with sharp points are charged, there will be greater surface charge density near the sharp points and the electric field near them will be high. This can ionise the surrounding air and can cause the charge to leak away. Thus a charged metal with sharp points will get discharged by this action.; the corona discharge.

If a line is threaded through 3 adjacent pulleys where it goes over the left, under the middle, and over the right pulley, and down to a load what is the mechanical advantage of the system.

### Visitors So Far @ AskPhysics

• 2,136,882 hits