Class 8 electricity: magnetic and heating effects with fibub

For students · Updated 2026-11-10 · For Class 8

Which fibub activities to use for Class 8 electricity: electromagnets, the heating effect of current and fuses, with good habits and a safe home experiment.

When current flows in a wire, two things happen that you cannot see: the wire gets warm, and it becomes a magnet. This is the story of Class 8 chapter 4, “Electricity: Magnetic and Heating Effects”. Fibub has free practice activities that let you try both effects without a spark or a burn. Use them on a phone or computer, no sign-up needed. Start with the simple circuit lab, then the electromagnet builder, then the fuse heating page.

What you will learn

• A circuit needs a complete loop, a source such as a cell, and materials that let current flow.
• A current-carrying coil acts like a magnet. This is the magnetic effect.
• An iron core makes the magnet much stronger. That is an electromagnet.
• Current makes a wire hot. This is the heating effect.
• A fuse is a thin wire that melts when too much current flows, and it protects a home.

Which activity to use when

Later, in Class 10, the ohm's law lab shows how current, voltage and resistance fit together. You do not need it yet.

How to use them properly

1. Predict first. Before you press anything, write down what you think will happen. If you guess first, you learn more from being right or wrong.
2. Change one thing at a time. In the electromagnet builder, change the number of turns and leave the cells alone. Then change the cells and leave the turns. Otherwise you cannot tell which change did the work.
3. Write units. Current is in amperes (A), voltage in volts (V), temperature in degrees Celsius. A number without a unit is only half an answer.
4. Check your answer. Does it make sense? More turns should not give a weaker coil, other things equal. If it does, look again.
5. Say it in words. After each try, write one sentence, such as “With the nail out, the coil picked up no clips.”
6. Treat numbers as a guide. These activities are simple models, not exact measurements of real wire.

Try this at home

Ask an adult to be with you. You need only one ordinary 1.5 V dry cell (an AA or D torch cell; never a rechargeable, lithium, button or car battery), a length of thin insulated wire (about 1 m) and an iron nail.

1. Wind the wire tightly round the nail about 20 times, leaving both ends free.
2. Ask the adult to strip about 2 cm of plastic off the two ends. Then touch them to the two ends of the cell for a few seconds only.
3. Bring the nail near a few paper clips. Do they jump to it?
4. Take the wire off the cell. Do the clips drop?
5. Wind 40 turns and try again. Is it stronger?

The wire and the cell may get warm, because the wire joins the two ends of the cell directly, so do not hold it on for long. If anything gets hot, let go and wait for it to cool. Never use a socket, a plug or any mains wire for these experiments. Mains electricity can kill. The activities on fibub show you the dangerous parts safely, so you never need to touch them.

Check yourself

1. You take the iron nail out of an electromagnet. What happens to its strength?
2. If the current in a wire is doubled, how many times more heat is made each second?
3. Why is a fuse wire made of a metal that melts easily?

Answers

1. It becomes much weaker, because the iron core is what makes the magnet strong.
2. Four times more, because heat grows with the square of the current (2 × 2 = 4).
3. So that it is the first thing to melt when too much current flows. The gap stops the current, and the house wiring stays safe.