Chapter 1 Flashcards
(23 cards)
What is a standard in measurements?
An absolute primary reference
Standards serve as the baseline for calibrating instruments.
Define calibration.
The process of configuring an instrument to match with standards
Calibration ensures accuracy in measurements.
What is precision in measurements?
When several readings are close together (consistent) when a physical quantity is measured for a value
Precision indicates the repeatability of measurements.
What is accuracy in measurements?
How close a measurement is in comparison to the perfect/true value
Accuracy reflects the correctness of a measurement.
What is zero error?
Zero error in any instrument can either be positive or negative
An example includes a weighing balance showing a reading without an object.
Define least count.
The minimum measurable value that can be measured using an instrument or the value corresponding to each subdivision of a calibrated instrument
Least count indicates the instrument’s sensitivity.
What is parallax error?
When the level of eyesight is not perpendicular to the scale readings
Parallax error can lead to inaccurate readings.
Define mass.
The property of an object to resist any change in the state of motion
Mass is also a measure of the amount of matter in an object.
What is weight?
A downward force that acts on an object due to its mass (measured in newtons)
Weight varies with gravitational force.
Define density.
A ratio of mass to volume of a substance
Density is expressed as ρ = m/V.
How do you measure the length of a pendulum using Method 1?
Add the length of the string to the radius of the bob
This method accounts for the complete length of the pendulum.
How do you measure the length of a pendulum using Method 2?
By using a set square whose edge is aligned with the bob for a horizontal reference
This ensures accuracy in alignment.
What is the method for measuring the length of a circular object?
Use a string, wrap it around the object, and determine the length of the string using a ruler
Averaging measurements from different diametrical ends improves accuracy.
How do you measure the thickness of paper?
Measure the height of several sheets and divide by the number of sheets
This method provides an average thickness since a ruler cannot measure it directly.
What is the formula for the volume of a sphere?
V = (4/3) x πr³
Memorization of this formula is required for calculations.
What is the formula for the volume of a cube/cuboid?
V = l x b x h
This formula is essential for calculating the volume of rectangular objects.
What is the formula for the volume of a cone?
V = (1/3) x πr² x h
This formula is used for calculating the volume of conical shapes.
Explain the displacement method for measuring volume.
A certain volume of water must be put inside a measuring cylinder; drop the object and check the new volume
The volume of the displaced liquid equals the volume of the object.
How is density calculated?
Density = Mass/Volume (m/V or ρ)
This relationship is crucial for understanding material properties.
How do you measure the density of an unknown liquid?
Measure the mass of the empty measuring cylinder, add known volume of liquid, subtract initial mass from final mass
This method allows for accurate determination of liquid density.
What devices are used for measuring time?
Analogue clocks and digital timers (stopwatches)
Different devices can provide varying levels of precision.
True or False: The time taken to complete one oscillation of a pendulum is known as its time period.
True
Understanding the time period is essential for pendulum-related calculations.
How can the time period of a pendulum be measured more accurately?
Measure the time taken for several oscillations and divide by the number of oscillations
This averaging reduces uncertainties caused by reaction time.
