Curriculum
- 25 Sections
- 92 Lessons
- 70 Hours
- 1.1 - Physical quantities and measurement techniques5
- 1.1Use of rulers and measuring cylinders to find a length or a volume
- 1.2Describe how to measure a variety of time intervals using clocks and digital timers
- 1.3Determine an average value for a small distance and for a short interval of time by measuring multiples (including the period of oscillation of a pendulum)
- 1.4Quiz Test 1Copy10 Minutes2 Questions
- 1.5TestCopy
- 1.2 - Motion4
- 1.3 - Mass and weight1
- 1.4 - Density1
- 1.5 - Forces5
- 1.6 - Momentum1
- 1.7 - Energy, work and power5
- 1.8 - Pressure1
- 2.1 - Kinetic particle model of matter5
- 2.2 - Thermal properties and temperature5
- 2.3 - Transfer of thermal energy5
- 3.1 - General properties of waves6
- 3.2 - Light7
- 3.3 - Electromagnetic spectrum2
- 3.4 - Sound3
- 4.1 - Simple phenomenon of magnetism3
- 4.2 - Electrical quantities5
- 4.3 - Electric circuits7
- 18.1Circuit diagram – Circuit components and their functionsCopy
- 18.2Effective or equivalent resistance in series and parallel circuitsCopy
- 18.3Behaviour of series and parallel circuitsCopy
- 18.4Function of LDR (Light Dependent Resistor) and thermistorCopy
- 18.5Potential divider and potentiometerCopy
- 18.6Use of relay in a circuitCopy
- 18.7Diode in half and full wave rectifier bridgeCopy
- 4.4 - Electrical safety2
- 4.5 - Electromagnetic effects6
- 5.1 - The nuclear model of the atom2
- 5.2 - Radioactivity5
- 6.1 - Earth and the Solar System2
- 6.2 - Stars and the Universe3
- Paper 6 instructions3
Describe how to measure a variety of time intervals using clocks and digital timers
Learning Objectives
- Measure a variety of time intervals using clocks and digital timers.
Contents to learn
Time
The S.I. unit of time is second.
Initially, a second was taken as 1/86400 of a mean solar day of the whole year of 1900 AD.
In the General Conference on Weight and Measure in 1967 the second was redefined as “the time interval taken by 9192631770 vibrations of cesium-133 atom under specified condition”.
Multiples/submultiples of time
| 1 day | 24 hours (h) |
| 1 hour (h) | 60 minute (min) |
| 1 minute (min) | 60 second (s) |
| 1 second (s) | 1000 millisecond (ms) |
| 1 milli-second | 1000 microsecond (µs) |
Measurement of time
Time is measured in years, months, days, hours, minutes and seconds. Due to the wide range of time intervals, different types of clocks and watches are used as summarized in the table.
| Types of Clocks | Use and Accuracy |
| Atomic Clock | Measure very short time intervals of about 10-10 seconds |
| Digital stopwatch | Measure short time intervals ( in minutes and seconds) to an accuracy of ±0.01s |
| Analogue stopwatch | Measure short time intervals ( in minutes and seconds) to an accuracy of ±0.1s |
| Ticker-tape timer | Measures short time intervals of 0.02s |
| Watch | Measure longer time intervals in hours, minutes and seconds. |
| Pendulum clock | Measure longer time intervals in hours, minutes and seconds. |
| Radioactive decay clock | Use to measure long time intervals of years to thousands of years |
Clock
It can be read in hours, minutes and seconds.
The clock is set to commence at a particular time or the start time is noted. The time events are then allowed to occur, and at the end of the event, the end time is noted. The difference provides the required time interval.
The accuracy of the clock is ±1 s
Digital timer
A digital timer is an electronic device used to measure time intervals accurately in digital format. Unlike traditional mechanical timers that rely on physical mechanisms such as gears and springs, digital timers use electronic components like microprocessors, integrated circuits, and display screens to measure and display time digitally.
Digital timers can measure time intervals with high precision of milliseconds or microseconds, depending on the device’s capabilities.
