PHYSICS ATP TIPS, EXPERIMENTS AND FEQs

[Suchal Riaz]

I will try to put everything i have learned from doing past papers into nutshell.

Frequently examined question:​

• theory suggests that resistance should be 10 ohm but in experiment value is 12. Given that experiment had no errors, does this experiment support theory?Experiment supports theory as the result is very close to theoretical value. it is not exact due to resistance of wire changes with time and the resistance of amm meter is not counted.
• Student has decided to repeat this experiment what she needs to keep constant?
  (u can write any variable that affects the results such as) the volume of water in container, room temperature, the distance of string from centre.
• Bottom of the object is not visible on the screen, how to adjust it?
  object, image and lens should be in line(their horizontal axis must be same)
• The image is not sharp(blurred), WHY is not sharp and HOW can u sharp this image?
  It is not sharp as light from object does not meet at single point. u can correct it by adjusting screen/lens so that the screen is exactly at the focal distance of lens.
• Why angle of incidence is not same as angle of reflection?
  The lines were too thick. normal was not drawn accurately. parallax error
• How to accurately measure the thickness of coins?
  place atleast 10 coins. take their thickness. divide by 10. OR use micrometer screw guage.
• Why it is not possible to take length XY with a single ruler?
  because the blank space will affect accuracy of result therefore second ruler is needed to measure the blank-space and subtract it from final answer.
• Why it is important for the rule to be very close to XY.
  to take accurate reading by avoiding parallax error.
• How to avoid parallax error?
  By keeping line of sight perpendicular to the scale.
• Why ammeter has been deflected to -2 written on other side of the zero?
  wrong connection of terminals/positive wire connected with negative wire.
• Why there are two negative terminals on a volt meter marked 3V and 10 V?When connected to 3V the range will be 0-3V and when connected to 10V the range will be 0-10V. it is useful for measuring accurately more ranges of voltages.
• The current is approximately 3 A. which range should student use, 0-10A or 0-5A.
  the smallest range that can accommodate the required current. therefore 0-5A
• How to measure the volume of irregular shaped object?
  By putting fixed volume of liquid in measuring cylinder and taking the initial reading. then add object and take final reading. then subtract initial from final.
• Why is resistance of R set to maximum before closing switch?
  so that current is lowest on start and increased in decreasing resistance as more in needed. to avoid equipments from malfunctioning.
• How to make sure the results are accurate?
  1-the N oscilations and then divide the Tn By N to get T
  2-Take many readings and average them.
  3-Take reading for different values of I then plot I against V. draw a best fit and then find V/I(resistance)
• Why the reading is taken for 20 oscillations?
  to reduce human error in reading time. as average will be less affected as proportion of delay will be less in 20 oscilations.

I will add more as i remember. i will add experiments and important tips as well..​

 

[Suchal Riaz]

BEST FIT EXAMPLE​

​

This might be helpful as well.

 

[GorgeousEyes]

https://www.xtremepapers.com/commun...aper-6-final-revision-tips.25517/#post-520735
This will help too

 

[Suchal Riaz]

HOW TO FIND FOCAL LENGTH OF COVEX LENS
VERY ACCURATE
in figure 1, a mirror, lens and object are on same axid prependicular to surface. the light from the object goes to lens get parallel come back and create image beside object. when the image is clear that length is accurate focal length.
To GUESS:
parallel rays from a distant object such as sun pass through lens and the lens produce image on paper. when the image is sharp the length is focal length.

 

[sweetiepie]

https://www.xtremepapers.com/community/threads/atp-notes.20798/ i added here

 

[GorgeousEyes]

Your tips are really helpful thank u , but could you explain to me tip no1 ?

 

[GorgeousEyes]

Why is resistance of R set to maximum before closing switch?
so that current is lowest on start and increased in decreasing resistance as more in needed. to avoid equipments from malfunctioning.
and this also .

 

[Suchal Riaz]

Your tips are really helpful thank u , but could you explain to me tip no1 ?

i dont remember those papers which i did probably first variants or igcse atp.
we found combined resistance of 3 resistors and the sum of the resistors. theoratically they must be same, but they are not. we have to say whether theory is supported by evidence or not. actually it is supprted as the value was very very close. it was provided that there is no error such as zero error or parallax error.

 

[GorgeousEyes]

i dont remember those papers which i did probably first variants or igcse atp.
we found combined resistance of 3 resistors and the sum of the resistors. theoratically they must be same, but they are not. we have to say whether theory is supported by evidence or not. actually it is supprted as the value was very very close. it was provided that there is no error such as zero error or parallax error.

THANK YOU

 

[Saad Mughal]

Hello Peepalz!
Experiments for Physics ATP:

HEAT:
Calculating Heat Capacity:
Apparatus: Solid block (specific heat capacity of which is to measured), Drill, Thermometer, Heater (of known power), Cotton wool.
Procedure:
-Drill two holes in the block.
-Measure the mass of the block.
-Place the heater in one of the blocks, the thermometer in the other.
- Use cotton wool to properly insulate/lag the block.
-Note the initial temperature of block.
- Turn on the heater for 300s.
-Calculate Heat Energy Supplied by heater using formula Q=Pt.
-Note the final temperature of block.
-Specific heat capacity = Q/m*(change in temperature).

Calculating Cooling Rate of Water:
Apparatus: Heater, Thermometer, Beaker, Stopwatch, Beaker containing Water.
Procedure:
-Place the heater into the beaker and turn it on to raise the temperature of water to 60 deg.
-Stir the contents of the water and place thermometer into the beaker.
-Note the starting temperature and turn on the stopwatch.
-Take readings of the thermometer and stopwatch at regular intervals (for e.g. 60 sec).
-Draw up a table and plot a graph to conclude your experiment.

Discussing the Cooling Effect of Evaporation.
Apparatus: Clothe, Tap, Thread, Beaker containing water at r.t.p, Thermometer.
-Wet the clothe by running tap water on it, when it is completely soaked, tie it to the sides of the beaker using the thread.
-Place the thermometer in the water and note the reading.
-After 2-3 regular intervals note the reading.
-The temperature will be lower than the initial temperature hence proving that evaporation causes cooling.

Picking a better insulator:
Apparatus: Two large cans, two small cans, cotton wool, polystyrene beads, boiling water, thermometers, stopwatch.
Procedure:
-Put the small cans into the large cans and insulate the small can with the help of (a) cotton wool and (b)polystyrene beads.
-Pour the boiling water into the small cans and place the thermometers in them.
-Start the stopwatch and take readings of temperature at regular intervals.
-Plot two tables for each insulator.
-The small can that has the higher temperature over the fixed period is better insulated.
-Hence, the object that provides a less temperature loss over the period is the better insulator.

LIGHT:
Refraction of Light using Ray Box:
Apparatus: Ray Box, Rectangular piece of glass, Plain paper, Pencil..
Procedure:
-Place the Plain paper below the rectangular piece of glass.
-Project a ray towards the glass.
-Make two points to mark the incident ray, two to mark the refracted ray and two to mark the emergent ray.
-Join all the lines. Measure the angles. Calculate refractive index.
-Repeat with different angles. Snell's law - Shown.

Reflection of Light using Pins:
Apparatus: Pins, Mirror.
Procedure:
-Place two pins infront of the prism to represent the incident ray.
-Look for the reflection of the pins on the mirror.
-Place the pins on the reflection to represent reflected ray.
-Draw a normal and measure the angles.
-Angle i = Angle r, proving laws of reflection.

ELECTRICITY:
Effect of temperature on resistor:
Apparatus: Resistor, Battery, Connecting wires, Ammeter, Voltmeter, Oven.
Procedure:
-Make a circuit with the battery, connecting wires, ammeter and voltmeter, resistor.
-Measure the resistance of the resistor using the formula R=V/I.
-Heat the resistor in the oven. Place the resistor back into the circuit.
-Measure the readings again and calculate R=V/I.
-Draw up a conclusion about how the resistance increases as temperature increases.

SOUND:
Speed of Sound (direct method):
Apparatus: Two observers, Gun, Stopwatch.
-The two observers are set apart at a known distance.
-One observer has the gun, the other has the stopwatch.
-Observer A fires the gun, Observer B starts the stopwatch when he sees the puff of smoke.
-Observer B stops the stopwatch when he hears the sound. The time is noted.
-Speed = Distance/Time is applied.
-The observers swap positions and repeat the experiment.
-The values are averaged and the speed of sound is obtained.

Speed of Sound (indirect method):
Apparatus: Two observers, Large building, stopwatch.
Procedure:
-The observers are stand side by side, their distance from the building is measured.
-Observer A yells/claps. Observer B starts the stopwatch on hearing the first yell.
-Observer B stops the stopwatch when he hears the echo.
-Speed = 2*distance/time.

These are all I can remember for now. I'll add more if I remember.

 

[Kidwai11]

Thank you all for these last minute tips...Really helping! Thanks n Good Luck for tomro! I'A we'll all do well.

 

[Suchal Riaz]

Experiment post has been updated. https://www.xtremepapers.com/commun...-tips-experiments-and-feqs.25526/#post-520817

 

[Saad Mughal]

This is all I have for tomorrow.
I'm not particularly very good at this ATP so the tips/notes are not like yesterday.
robinhoodmustafa.

 

[robinhoodmustafa]

I just notice Saad Mughal in ATP paper they dont ask us Formula or use it to find answer ThankGod.

If u have a practical mind than the paper is easy.

 

[Saad Mughal]

I just notice Saad Mughal in ATP paper they dont ask us Formula or use it to find answer ThankGod.

If u have a practical mind than the paper is easy.

Actually, they don't ask but its good to know because when you're calculating something and you state the formula then the examiner considers the working (if we write the wrong answer).
Practical mind? Physics ATP is out of this world. I mean since when do schools conduct open ground experiments for lenses and sound?

 

[robinhoodmustafa]

Actually, they don't ask but its good to know because when you're calculating something and you state the formula then the examiner considers the working (if we write the wrong answer).
Practical mind? Physics ATP is out of this world. I mean since when do schools conduct open ground experiments for lenses and sound?

Ok. lenses is tough. I Prefer light ray diagram.. They tell us to join this and that line
but Sound is easy.. Echo , Sound through medium etc is something we know from childhood

 

[qasim9]

is

Hello Peepalz!
Experiments for Physics ATP:

HEAT:
Calculating Heat Capacity:
Apparatus: Solid block (specific heat capacity of which is to measured), Drill, Thermometer, Heater (of known power), Cotton wool.
Procedure:
-Drill two holes in the block.
-Measure the mass of the block.
-Place the heater in one of the blocks, the thermometer in the other.
- Use cotton wool to properly insulate/lag the block.
-Note the initial temperature of block.
- Turn on the heater for 300s.
-Calculate Heat Energy Supplied by heater using formula Q=Pt.
-Note the final temperature of block.
-Specific heat capacity = Q/m*(change in temperature).

Calculating Cooling Rate of Water:
Apparatus: Heater, Thermometer, Beaker, Stopwatch, Beaker containing Water.
Procedure:
-Place the heater into the beaker and turn it on to raise the temperature of water to 60 deg.
-Stir the contents of the water and place thermometer into the beaker.
-Note the starting temperature and turn on the stopwatch.
-Take readings of the thermometer and stopwatch at regular intervals (for e.g. 60 sec).
-Draw up a table and plot a graph to conclude your experiment.

Discussing the Cooling Effect of Evaporation.
Apparatus: Clothe, Tap, Thread, Beaker containing water at r.t.p, Thermometer.
-Wet the clothe by running tap water on it, when it is completely soaked, tie it to the sides of the beaker using the thread.
-Place the thermometer in the water and note the reading.
-After 2-3 regular intervals note the reading.
-The temperature will be lower than the initial temperature hence proving that evaporation causes cooling.

Picking a better insulator:
Apparatus: Two large cans, two small cans, cotton wool, polystyrene beads, boiling water, thermometers, stopwatch.
Procedure:
-Put the small cans into the large cans and insulate the small can with the help of (a) cotton wool and (b)polystyrene beads.
-Pour the boiling water into the small cans and place the thermometers in them.
-Start the stopwatch and take readings of temperature at regular intervals.
-Plot two tables for each insulator.
-The small can that has the higher temperature over the fixed period is better insulated.
-Hence, the object that provides a less temperature loss over the period is the better insulator.

LIGHT:
Refraction of Light using Ray Box:
Apparatus: Ray Box, Rectangular piece of glass, Plain paper, Pencil..
Procedure:
-Place the Plain paper below the rectangular piece of glass.
-Project a ray towards the glass.
-Make two points to mark the incident ray, two to mark the refracted ray and two to mark the emergent ray.
-Join all the lines. Measure the angles. Calculate refractive index.
-Repeat with different angles. Snell's law - Shown.

Reflection of Light using Pins:
Apparatus: Pins, Mirror.
Procedure:
-Place two pins infront of the prism to represent the incident ray.
-Look for the reflection of the pins on the mirror.
-Place the pins on the reflection to represent reflected ray.
-Draw a normal and measure the angles.
-Angle i = Angle r, proving laws of reflection.

ELECTRICITY:
Effect of temperature on resistor:
Apparatus: Resistor, Battery, Connecting wires, Ammeter, Voltmeter, Oven.
Procedure:
-Make a circuit with the battery, connecting wires, ammeter and voltmeter, resistor.
-Measure the resistance of the resistor using the formula R=V/I.
-Heat the resistor in the oven. Place the resistor back into the circuit.
-Measure the readings again and calculate R=V/I.
-Draw up a conclusion about how the resistance increases as temperature increases.

SOUND:
Speed of Sound (direct method):
Apparatus: Two observers, Gun, Stopwatch.
-The two observers are set apart at a known distance.
-One observer has the gun, the other has the stopwatch.
-Observer A fires the gun, Observer B starts the stopwatch when he sees the puff of smoke.
-Observer B stops the stopwatch when he hears the sound. The time is noted.
-Speed = Distance/Time is applied.
-The observers swap positions and repeat the experiment.
-The values are averaged and the speed of sound is obtained.

Speed of Sound (indirect method):
Apparatus: Two observers, Large building, stopwatch.
Procedure:
-The observers are stand side by side, their distance from the building is measured.
-Observer A yells/claps. Observer B starts the stopwatch on hearing the first yell.
-Observer B stops the stopwatch when he hears the echo.
-Speed = 2*distance/time.

These are all I can remember for now. I'll add more if I remember.

there aany setup to measure thermistor ??
i don't remember what the real question was ..

 

[Kidwai11]

Hi,
Was just wondering... In the paper 6 exam, when you're asked to draw a graph... I always draw the entire graph with a sharp pencil... But when doing biology and chemistry paper 6, i realised that with a pencil, when DRAWING THE X AND Y AXIS, the pencil is a bit hard to see... Do u guys think that we are allowed to use a black pen for the axis and then to plot the data and the line of best fit, we can use a sharpened pencil?
What do u think? Thanks!

 

[Saad Mughal]

Ok. lenses is tough. I Prefer light ray diagram.. They tell us to join this and that line
but Sound is easy.. Echo , Sound through medium etc is something we know from childhood

They're easy.
I was referring to the fact that this is an alternative to PRACTICAL and such bizarre experiments are conducted.

 

[Saad Mughal]

Hi,
Was just wondering... In the paper 6 exam, when you're asked to draw a graph... I always draw the entire graph with a sharp pencil... But when doing biology and chemistry paper 6, i realised that with a pencil, when DRAWING THE X AND Y AXIS, the pencil is a bit hard to see... Do u guys think that we are allowed to use a black pen for the axis and then to plot the data and the line of best fit, we can use a sharpened pencil?
What do u think? Thanks!

For the axis, you can use pen.