1.1 Physical Quantities and Measurement Techniques Flashcards
(22 cards)
What is a physical quantity?
A physical quantity is anything that can be measured and consists of a magnitude and a unit.
Examples: length, mass, time, temperature, force.
What instrument is used to measure length?
A ruler or meter rule is used to measure length.
What instrument is used to measure the volume of a liquid?
A measuring cylinder is used to measure the volume of liquids.
How can we measure a variety of time intervals in physics?
Time intervals can be measured using clocks (analog) and digital timers.
Clocks are used for longer durations.
Digital timers are used for short, precise time intervals, like in experiments.
How do you calculate the period of oscillation?
Period of oscillation = Time taken / Number of swings
This gives the time for one complete swing.
What is a scalar quantity?
A scalar quantity is a physical quantity that has only magnitude and no direction.
Examples: mass, speed, distance, time, energy.
What is a vector quantity?
A vector quantity is a physical quantity that has both magnitude and direction.
Examples: velocity, force, displacement, acceleration.
How do you calculate the resultant force of two vectors at right angles?
The resultant force of two vectors at right angles is calculated using Pythagoras’ theorem:
Resultant force (R) = √(F₁² + F₂²)
Where F₁ and F₂ are the magnitudes of the two vectors.
How much are 1.Micrometer, 2.Nanometer, 3.Gigameter 4. Deciliter
Micrometer - 10⁻⁶
Nanometer - 10⁻⁹
Gigameter - 10⁹
Deciliter - 10⁻¹
Area of a square
length * breadth
Area of a triangle
1 ⁄ 2 * base * height
Area of a circle
π r²
Volume of a rectangular block
volume = length × breadth × height
Volume of a cylinder
π r² h
What instruments can be used to measure very short time intervals?
Tickertape timers
or dataloggers are often used to record short time
intervals in motion experiments.
Why are tickertape timers effective for short time intervals?
Ten ticks, rather than single ticks, are used in tickertape timers.
What is systematic error?
Systematic error is an error that affects all measurements in the same way, making them all consistently too high or too low.
It is usually caused by faulty equipment, incorrect calibration, or a consistent mistake in the method.
What is the precision of Vernier scale?
0.5mm
What is the precision of micrometer screw gauge?
0.001cm
In the case of two vectors Fₓ and Fᵧ acting at right
angles to each other at a point, how can the angle be calculated between Fₓ and F resultant.
tan θ = Fᵧ / Fₓ
How do you find the resultant force of two forces acting in a straight line?
When two forces act in the same straight line, the resultant force is found by adding them together.
If the forces are in the same direction, you add their magnitudes.
If the forces are in opposite directions, you subtract their magnitudes.
