NIOS Class 10 Science Activity 16.4 Electrical Energy

In this activity, we will discuss the thermal effect of electric current flowing in a coil.

Electrical Energy Activity

This activity is based on the NIOS Class 10 science and technology (212) Chapter 16- Electrical Energy, Module 4.

Thermal Effect of Electric Current

Aim

To study the heating effect of electric current and factors affecting it

Materials Used

   1.  Two coils (10 turns and 20 turns)

   2. Two dry cells

   3. Connecting wires

Procedure

 We take two heater coils (10 turns and 20 turns) and perform the experiment separately with each coil.

 We join the connecting wires to the free ends of the 10-turn coil, and then the other ends of these wires are connected to a dry cell (1.5 volts) for 10 seconds. We touch the coil to feel any change in the temperature. We repeat this experiment for 20 seconds.

 Now we connect two dry cells (1.5 volts each) and observe the temperature change.

 Finally, we repeat the same experiment with a 20-turn coil and record the change in the temperature.

 

Observation

The coil becomes warm when current is passed through it. We observe that:

   1. More heat is produced when current is passed for a long time.

   2. More heat is produced when high voltage (two or more cells) is connected to the coil.

   3. Less heat is produced when the number of turns in the coil increases.

Coil	Cell	Time	Observation	Temp.
10 turns	1.5 volt	10 seconds	Slightly hot	35ºC
10 turns	1.5 volt	20 seconds	Hot	40ºC
10 turns	3 volt	10 seconds	Hot	45ºC
20 turns	1.5 volt	10 seconds	Slightly hot	32ºC
20 turns	1.5 volt	20 seconds	Hot	35ºC
20 turns	3 volt	10 seconds	Hot	40ºC

 

Explanation

When an electric current is passed through a conductor, electrical energy is converted into heat energy due to the resistance of the conductor.

The heating depends on – (i) Current, (ii) Duration, (iii) Voltag,e (iv) Resistance

When an electric current is passed for a long time, more heat is produced.

When the voltage is increased in the circuit, more heat is produced.

More turns in the coil increase its resistance, reducing the current flow so less heat is produced.

Conclusion

We can conclude that heat is produced in a conductor when an electric current is passed. More heat is produced when a higher potential difference is applied or when current flows for a long time, or the resistance of the coil is low.

 So, the activity explains the thermal effect of electric current.

Frequently Asked Questions

   1. How does the increase in voltage affect heating in the coil?

Answer – When the voltage increases, more current flows through the coil, which produces more heat.

   2. Does the duration of the current flow affect the heating effect?

Answer – Yes, when electric current flows for a long time, more heat is produced.

   3. Why does the coil get heated when current passes through it?

Answer- The coil gets heated because the resistance of the coil is offered to the current,so the electrical energy is converted into heat energy.