- Messages
- 19
- Reaction score
- 3
- Points
- 0
micrometer : can measure the thickness of any small thing to 0.01 mm
vernier : can measure the inner and outer wall of anything to 1.05mm
Control Variables
Precautions
Units ( eg.. voltage is V etc. ) cause the units hold 1 mark of the question
Statements & justification
The rest are calculations and measurements
To produce more accurate or reliable results:
• Repeat experiment, to calculate average reading.
• Avoiding parallax error, look perpendicular to the ruler.
• If accuracy in measurement was asked, check for zero error.
Improvements that could be done to the experiment (temp. cooling):
• Same initial temperature.
• Same volume of water.
• Same shape of beaker.
• Beakers of same surface.
• Same room temperature.
• Stirring the water in the beakers.
• Same time intervals.
• Same surface area. (Unless given different containers)
• Adding water or cooling effect at regular intervals.
Heat loss could be reduced by:
• Insulation of beaker.
• Covering beaker with a lid.
For 2 values to be directly proportional,
• The graph of the values must be a straight line from the origin.
• As value 1 increase, value 2 increases.
For images produced from lenses on screens, precautions taken:
• Use of a darkened room for the experiment.
• Avoiding parallax error in measurement, and look perpendicular to the ruler.
• Object and lens at the same height from bench.
• Object/lens/screen is perpendicular to the bench.
To draw an image created from lens:
• Inverted from the original object.
• Sides are multiplied by the magnification.
*If values have difference by 0.1 or 0.01, that is the limit of experimental accuracy, so answers are about the same.
For spring extension experiment, variables that should be constant in the experiment:
• Number of coils.
• Diameter of spring.
• Selection of loads.
• Mass of spring.
for improving the accuracy of the results (for experiments):
Minimizing heating effect of a current:
• Lower current
• Increase voltage
• Add a lamp
• Increase resistance of a resistor
To increase accuracy of ray diagrams
• View bases of pins since pins may not be vertical
• Keep pins further apart
• Use more pins
• Avoid parallax, explain action and reason
• Repeats and average
Adjustments made to experiments will be made to increase accuracy
Improvement made to experiments about heating effect and insulation
• Lids
• Repeats
• Stirring
• Record max. Temperature
• Add insulation
• Keep constant room temperature
• Avoid heat loss
How to check if a rule is vertical:
• Protractor
• Use of set square
• Plumb line
• Spirit Level
Precautions taken in experiments about formation of images by a lens
• Use a darkened area
• Meter ruler on bench or clamped
• Object and lens same height on bench
• Mark on lens holder to show center of lens
• Take more readings
• Avoid parallax error, explain action and reason
• Lens\screen perpendicular to bench
Variables in experiments about springs and stretching effect:
• Number of coils
• Length of spring
• Diameter\thickness of spring or wire
• Range of loads
• Length of wire
• Coil spring
Periodic time (T) is measured by timing a number
of oscillations, then divide the time taken for all the oscillations by the number of oscillations
Drawing graphs:
• Label axis
• Choose a proper scale
• Well judged best fit line
• Thin and neat lines
Measuring the gradient:
• Draw a triangle on graph
• Use clear lines
• Triangle must be larger than half the line
Sources of error in calculating circumference by string method:
• Parallax
• Diagonal winding
• Thickness of string
Improvement made to calculating circumference by string method
• Avoid parallax error
• Repeats and average
• Thinner string
• Parallel winding of springs
It's not the BEST list in the world, but hopefully it will help... :wink:
Best of luck, Inshallah we'll all get A*
vernier : can measure the inner and outer wall of anything to 1.05mm
Control Variables
Precautions
Units ( eg.. voltage is V etc. ) cause the units hold 1 mark of the question
Statements & justification
The rest are calculations and measurements
To produce more accurate or reliable results:
• Repeat experiment, to calculate average reading.
• Avoiding parallax error, look perpendicular to the ruler.
• If accuracy in measurement was asked, check for zero error.
Improvements that could be done to the experiment (temp. cooling):
• Same initial temperature.
• Same volume of water.
• Same shape of beaker.
• Beakers of same surface.
• Same room temperature.
• Stirring the water in the beakers.
• Same time intervals.
• Same surface area. (Unless given different containers)
• Adding water or cooling effect at regular intervals.
Heat loss could be reduced by:
• Insulation of beaker.
• Covering beaker with a lid.
For 2 values to be directly proportional,
• The graph of the values must be a straight line from the origin.
• As value 1 increase, value 2 increases.
For images produced from lenses on screens, precautions taken:
• Use of a darkened room for the experiment.
• Avoiding parallax error in measurement, and look perpendicular to the ruler.
• Object and lens at the same height from bench.
• Object/lens/screen is perpendicular to the bench.
To draw an image created from lens:
• Inverted from the original object.
• Sides are multiplied by the magnification.
*If values have difference by 0.1 or 0.01, that is the limit of experimental accuracy, so answers are about the same.
For spring extension experiment, variables that should be constant in the experiment:
• Number of coils.
• Diameter of spring.
• Selection of loads.
• Mass of spring.
for improving the accuracy of the results (for experiments):
Minimizing heating effect of a current:
• Lower current
• Increase voltage
• Add a lamp
• Increase resistance of a resistor
To increase accuracy of ray diagrams
• View bases of pins since pins may not be vertical
• Keep pins further apart
• Use more pins
• Avoid parallax, explain action and reason
• Repeats and average
Adjustments made to experiments will be made to increase accuracy
Improvement made to experiments about heating effect and insulation
• Lids
• Repeats
• Stirring
• Record max. Temperature
• Add insulation
• Keep constant room temperature
• Avoid heat loss
How to check if a rule is vertical:
• Protractor
• Use of set square
• Plumb line
• Spirit Level
Precautions taken in experiments about formation of images by a lens
• Use a darkened area
• Meter ruler on bench or clamped
• Object and lens same height on bench
• Mark on lens holder to show center of lens
• Take more readings
• Avoid parallax error, explain action and reason
• Lens\screen perpendicular to bench
Variables in experiments about springs and stretching effect:
• Number of coils
• Length of spring
• Diameter\thickness of spring or wire
• Range of loads
• Length of wire
• Coil spring
Periodic time (T) is measured by timing a number
of oscillations, then divide the time taken for all the oscillations by the number of oscillations Drawing graphs:
• Label axis
• Choose a proper scale
• Well judged best fit line
• Thin and neat lines
Measuring the gradient:
• Draw a triangle on graph
• Use clear lines
• Triangle must be larger than half the line
Sources of error in calculating circumference by string method:
• Parallax
• Diagonal winding
• Thickness of string
Improvement made to calculating circumference by string method
• Avoid parallax error
• Repeats and average
• Thinner string
• Parallel winding of springs
It's not the BEST list in the world, but hopefully it will help... :wink:
Best of luck, Inshallah we'll all get A*
