Question 3
THE MAGIC OF ELECTRICITY
Energy can change its form from one to another. For instance, light energy of the Sun is changed
to chemical energy by plants through photosyntesis process.
Objectives:
In this experiment you will observe the change of electricity into heat energy.
Materials:
- plastics cup (50 ml) with cover
- water
- cables and connectors
- coil
- batteries with holder
- thermometer
- timer
Procedures:
1\. Fill the plastics cup with 50 ml of water
2\. Connect the coil with connector then put it into the plastics cup. Make sure that whole coil is
immersed in water. (See figure below)
coil
3\. Put the cover of cup on the top of the cup and make sure that it can seal the cup properly (See
figure below)
cover
4\. Put the thermometer into the hole provided in the cover of cup (see figure below)
thermometer
5\. Put one battery (1.5V) on the battery holder properly.
Battery
holder
6\. Arrange the experimental apparatus according to the picture below.
7\. Measure the initial temperature of water in the plastics cup by using the thermometer provided.
Write down the measured temperature on the Table provided below.
8\. Connect the coil to the battery for 5 minutes. Disconnect coil and battery and then measure the
temperature of water by using the thermometer provided. Use the timer to measure the time.
Write down this measured temperature on the Table.
9\. Add one (1) battery serially to the circuit so that the voltage become 3.0 V and then repeat the
steps 7 and 8.
10\. Add one (1) more battery serially to the circuit so that the voltage become 4.5 V and then
repeat the steps 7 and 8 again.
11\. Calculate the difference between the temperature of water after 5 minutes heating and the
initial temperature for each voltage.
| No | Voltage (Volt) | Initial temperature of water (°C) | Temperature after 5 minutes Heating (°C) | Temperature Difference (°C) |
| --- | --- | --- | --- | --- |
| 1 | 1.5 | | | |
| 2 | 3.0 | | | |
| 3 | 4.5 | | | |
12\. Draw a graph of the temperature difference of water againts the change of the voltage.
0\.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Analysis:
If the amount of water is 50ml and the voltage is 1.0 V, predict the temperature of water.
Energy can change its form from one to another. For instance, light energy of the Sun is changed
to chemical energy by plants through photosyntesis process.
Objectives:
In this experiment you will observe the change of electricity into heat energy.
Materials:
- plastics cup (50 ml) with cover
- water
- cables and connectors
- coil
- batteries with holder
- thermometer
- timer
Procedures:
1\. Fill the plastics cup with 50 ml of water
2\. Connect the coil with connector then put it into the plastics cup. Make sure that whole coil is
immersed in water. (See figure below)
coil
3\. Put the cover of cup on the top of the cup and make sure that it can seal the cup properly (See
figure below)
cover
4\. Put the thermometer into the hole provided in the cover of cup (see figure below)
thermometer
5\. Put one battery (1.5V) on the battery holder properly.
Battery
holder
6\. Arrange the experimental apparatus according to the picture below.
7\. Measure the initial temperature of water in the plastics cup by using the thermometer provided.
Write down the measured temperature on the Table provided below.
8\. Connect the coil to the battery for 5 minutes. Disconnect coil and battery and then measure the
temperature of water by using the thermometer provided. Use the timer to measure the time.
Write down this measured temperature on the Table.
9\. Add one (1) battery serially to the circuit so that the voltage become 3.0 V and then repeat the
steps 7 and 8.
10\. Add one (1) more battery serially to the circuit so that the voltage become 4.5 V and then
repeat the steps 7 and 8 again.
11\. Calculate the difference between the temperature of water after 5 minutes heating and the
initial temperature for each voltage.
| No | Voltage (Volt) | Initial temperature of water (°C) | Temperature after 5 minutes Heating (°C) | Temperature Difference (°C) |
| --- | --- | --- | --- | --- |
| 1 | 1.5 | | | |
| 2 | 3.0 | | | |
| 3 | 4.5 | | | |
12\. Draw a graph of the temperature difference of water againts the change of the voltage.
0\.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
Analysis:
If the amount of water is 50ml and the voltage is 1.0 V, predict the temperature of water.