P.H.Y.S.I.C.S P2 D.O.U.B.T.S CIE

[sabrina]

systematic errors r errors which r affected to same extent. it is the instruments fault. it can be fully removed if the cause is known. whenever systematic errors occurs always check the zero error. in graphs we can find out if the error is systematic by seeing if the line passes through the origin or not.
random errors r errors which r affected to different extend. its experimenters fault. it can be minimize by repeating the experiment several times n finding out the average. in graphs we can find out if the error is random by scattering of lines  
hope its clear

[halosh92]

hey guys one question i had.... if i kept a filament in constant temperature lets say in Ice then would its IV graph be a straight line through origin

how is it possible to that...the filament itself will heat up because the current passing through it will heat it up i guess.
but maybe if u keep adding ice....and keep it constnt temp. then yea it will i guess. according to ohms law  

could someone answer my question plz

[Chingoo]

By definition, systematic error is an error having constant direction and magnitude in all readings. Consider a situation where your stopwatch starts from 0:00:10 s only; all your readings will have an additive 0.1 s. It will not vary with situations. Such an error can be eliminated by taking a difference/gradient. Consider you had to measure the time interval for a ball to fall between a distance XY; the first reading (when it crossed X) was 0:02:00 s, and the second reading (when it crossed Y) was 0:04:10 s. The time interval is the difference of the two:
4.10 - 2.00 = 2.10.
Even if the systematic error was absent, the DIFFERENCE would be the same i.e. 4.00 - 1.90 = 2.10 s.
Systematic errors do not affect the precision of a measurement, but they affect the accuracy.

By definition, random error is an error having a varying direction and magnitude in all readings. This is quite simple, for instance, given the same example as above--it is not possible for us to start the stopwatch at the exact moment the ball crosses X, as there is a human reaction error of 0.1 to 0.4 seconds. This error cannot be eliminated with a gradient or difference, because it is not constant. A random error does affect the precision of a measurement, but not its accuracy.

[Chingoo]

hey guys one question i had.... if i kept a filament in constant temperature lets say in Ice then would its IV graph be a straight line through origin

Like halosh said, if you keep the temperature of the filament constant by adding ice frequently, it will be a straight line through origin. Follow the rules of the Ohm's Law:
The current through a resistor is directly proportional to the potential difference across it if external conditions such as temperature and pressure remain constant.
Simple 

[sabrina]

By definition, systematic error is an error having constant direction and magnitude in all readings. Consider a situation where your stopwatch starts from 0:00:10 s only; all your readings will have an additive 0.01 s. It will not vary with situations. Such an error can be eliminated by taking a difference/gradient. Consider you had to measure the time interval for a ball to fall between a distance XY; the first reading (when it crossed X) was 0:02:00 s, and the second reading (when it crossed Y) was 0:04:10 s. The time interval is the difference of the two:
4.10 - 2.00 = 2.10.
Even if the systematic error was absent, the DIFFERENCE would be the same i.e. 4.00 - 2.10 = 2.10 s.
Systematic errors do not affect the precision of a measurement, but they affect the accuracy.

By definition, random error is an error having a varying direction and magnitude in all readings. This is quite simple, for instance, given the same example as above--it is not possible for us to start the stopwatch at the exact moment the ball crosses X, as there is a human reaction error of 0.1 to 0.4 seconds. This error cannot be eliminated with a gradient or difference, because it is not constant. A random error does affect the precision of a measurement, but not its accuracy.

wow good explanation.

[halosh92]

THANKYOU GUYS

[halosh92]

one more question wat exactly is
diffraction
interference
path difference
phase differenec
the exact cie meaning plz

[Asamy111]

m/j 09 .. q5 varient 1

[Meticulous]

one more question wat exactly is
diffraction
interference
path difference
phase differenec
the exact cie meaning plz

Diffraction-It is the word used to describe the way waves spread out as they bend through and around obstacles and gaps. Diffraction also describes the interaction between waves and solid objects.

Interference-It occurs when waves overlap each other to produce a pattern where the waves reinforce each other in some places & cancel each other out in others. This also could be the definition for superposition.

Phase Difference-The phase difference between 2 particles on a wave is the fraction of a cycle by which one moves behind the other. Measured in multiples of "pie"

Path Difference-Same as phase difference but in multiples of lambda

[halosh92]

m/j 09 .. q5 varient 1

the answer is here somewhere in this thread by "nid"
check the previous pages plz

[Chingoo]

one more question wat exactly is
diffraction
interference
path difference
phase differenec
the exact cie meaning plz

DIFFRACTION The spreading of waves about an obstacle or through a gap/aperture.
INTERFERENCE The superposition of waves which support each other at a point and cancel out each other's effect at another point.
The last two I'm not sure about.

[halosh92]

what are the conditions for interfernce?

[sabrina]

what are the conditions for interfernce?

1. should meet at a point
2. same type(means both should be either transverse or longitudinal)
3. same frequency, wavelength
4. if it is constructive interference so it should be in phase (path difference=lambda, phase difference=2pie)
5. if it is destructive interference so it should be out of phase (path difference=(2n+1)lambda/2, phase         difference=(2n+1)pie)
hope its clear

[sabrina]

guys how to do o/n2008 q7bii

[halosh92]

1. should meet at a point
2. same type(means both should be either transverse or longitudinal)
3. same frequency, wavelength
4. if it is constructive interference so it should be in phase (path difference=lambda, phase difference=2pie)
5. if it is destructive interference so it should be out of phase (path difference=(2n+1)lambda/2, phase         difference=(2n+1)pie)
hope its clear

shouldnt we mention something about coherence??
and r u sure about the formulas isnt it for constructive:
path difference: n lamda

and destructive:
path difference= (n + 1/2) lambda and phase differnce = pie