1029 science project ideas, from class 1 to college.

What it shows

Water stored high up has potential energy. As it falls it turns a turbine, and a generator on the turbine’s shaft turns that motion into electricity.

You will need

• A raised bottle or tank as the dam
• A pipe
• A turbine made from plastic spoons or a bottle cap
• A small DC motor as the generator
• An LED and wires

What it shows

Alternating current in the primary coil makes a changing magnetic field in the iron core, which induces a voltage in the secondary coil (mutual induction). In an ideal transformer the voltages are in the same ratio as the numbers of turns.

You will need

• A laminated iron core or a soft-iron ring
• Enamelled copper wire for two coils with different numbers of turns
• A low-voltage AC supply in the school lab
• An AC voltmeter or a small bulb

Safety: Never connect a home-made transformer to the mains. Use only a low-voltage AC supply, with your teacher.

What it shows

Piezoelectric discs make a small voltage when they are pressed. Many discs under a tile, with a rectifier and a capacitor, can light LEDs, though the energy from each step is very small.

You will need

• Piezo discs
• Diodes for a bridge rectifier
• A capacitor
• LEDs
• Plywood tiles and foam

What it shows

A single fixed pulley does not make a load lighter, but it changes the direction of the pull, so you lift a load up by pulling down. That is why cranes, flagpoles and wells use pulleys.

You will need

• An empty thread spool (free from a tailor)
• A pencil or a skewer to run through the spool
• A cardboard box or two chairs as the frame
• About 1 metre of string
• A small bucket made from a paper cup with a string handle
• Pebbles or coins as the load
• A rubber band to use as a simple force meter

Safety: Keep small pebbles and coins away from young children, and an adult must make the holes for the pencil.

Take it further: Add a second spool that hangs from the string and moves with the load, and show that the rubber band now stretches about half as much.

What it shows

Sound travels through the air as vibrations. A loud sound near a stretched plastic sheet makes the sheet vibrate, and grains of rice on it jump, even though nothing touches the drum.

You will need

• A large steel bowl or a wide-mouthed plastic container
• A piece of cling film or a cut-open plastic bag
• A rubber band to hold the film tight
• A spoonful of uncooked rice or sugar
• A steel plate and a spoon to make a loud sound, or a speaker playing music

Take it further: Put the drum in a sealed box with a thick blanket round it and test whether sound still gets through.

What it shows

A movable pulley hanging with the load shares the weight between two lengths of string, so you need only about half the force to lift it, but you must pull twice as much string. Adding pulleys trades distance for force.

You will need

• Two empty thread spools and two pencils or skewers
• A wire coat hanger or a wooden frame to hold the top spool
• About 2 metres of string
• A water bottle half full as the load
• A rubber band or a spring balance to compare the pull
• Two bent paper clips or wire hooks
• A ruler

Safety: An adult must bend the wire hooks, and the load should be lifted only a little way above a soft surface.

Take it further: Add a third spool and work out how many string lengths support the load and what fraction of the effort is now needed.

What it shows

Stroking a steel needle with a magnet turns it into a weak magnet. Floated on water so it can turn freely, the needle lines up north to south, because the Earth itself acts like a giant magnet.

You will need

• A steel sewing needle
• A bar magnet or a strong fridge magnet
• A small piece of cork, thermocol or a bottle cap to float the needle on
• A bowl of water
• A compass app on a phone or a real compass, to check

Safety: Needles are sharp; an adult must help young children to handle and push the needle into the cork.

Take it further: Use the compass to draw a map of your school ground, marking which way each building faces.

What it shows

Warm air is lighter than cool air and rises. A paper spiral hung above a warm surface spins as the rising air pushes on its sloping coils, showing convection, the way heat spreads in air and water.

You will need

• A sheet of thin paper or an old magazine page (free)
• Scissors and a pencil
• About 30 cm of thread and a needle or tape
• A cup of hot water, a warm lamp with an ordinary bulb, or a sunny windowsill as the heat source

Safety: An adult must pour the hot water and the spiral must hang well above it; never hang paper over a flame or a gas stove.

Take it further: Hold a thin strip of tissue paper beside a hot cup, then above it, to find which way the air is flowing at different places.

What it shows

A sachet with a small air bubble just floats in a bottle of water. Squeezing the bottle raises the pressure, squashes the bubble, and the sachet becomes denser and sinks; let go and it rises. Submarines and fish control their depth the same way.

You will need

• A clear plastic bottle with a cap, 1 litre or more (free)
• A sealed ketchup or soy sauce sachet with a small air bubble inside
• Water
• A bowl to test the sachet first

Take it further: Make a diver from the cut-off top of a dropper or a pen cap weighted with a blob of clay, and tune its air bubble until it just floats.

What it shows

A cardboard bird with coins hidden in its wing tips balances on its beak and even wobbles back upright when pushed. Adding weight far forward and low moves the bird’s centre of gravity to just below the beak, so it cannot topple.

You will need

• Stiff cardboard from a carton (free)
• Two one-rupee coins or two washers
• Scissors, pencil and glue or tape
• Colours to decorate
• A pencil or your finger as the balancing point

Safety: Children should use safety scissors on cardboard; an adult can cut thicker card.

Take it further: Make a balancing clown from a cork and two forks, or a balancing butterfly from a sweet wrapper and two coins.

What it shows

Levers differ by where the fulcrum, load and effort sit. A seesaw has the fulcrum in the middle, a wheelbarrow has the load in the middle, and tongs have the effort in the middle. Three working ice cream stick levers on one board show each class and how much they help.

You will need

• A cardboard or plywood base about 40 cm by 30 cm
• Six ice cream sticks or thin wooden strips
• Three paper fasteners or small nails as hinges
• Three bottle caps as load holders and coins as loads
• Rubber bands as force meters
• Glue, tape and labels

Safety: An adult must hammer any nails and help with the paper fasteners; keep coins away from small children.

Take it further: Measure the distances from the fulcrum to the load and the effort on each lever and work out the mechanical advantage as load arm divided by effort arm.

What it shows

A drop of water on clear plastic has a curved top, like a convex lens, and makes small print look bigger. A rounder, smaller drop magnifies more. It shows how lenses in magnifying glasses, spectacles and microscopes work.

You will need

• A clear plastic sheet, a CD case or a piece of cling film stretched over a cup (free)
• Water and a dropper or a straw
• A newspaper with small print
• A piece of wire bent into a small loop for the extension
• A ruler

Take it further: Make a microscope with a water drop over a pinhole in a card and look at an onion skin or a hair.

What it shows

In a series circuit the same current flows through every bulb and the voltage is shared, so each bulb glows dimly and all go out if one is removed. In parallel each bulb gets the full cell voltage, glows brightly, and the others stay lit when one is removed.

You will need

• Six 2.5 V torch bulbs with holders (about Rs 10 each)
• Two AA cells in a holder (3 V)
• A cardboard or plywood board about 30 cm by 40 cm
• Insulated single-strand wire, 3 m
• Three slide switches or paper-clip switches
• A multimeter to read current and voltage
• Drawing pins and glue

Safety: Cells only, never mains. Bulbs and wires get slightly warm; switch off when not demonstrating. An adult must help with the cutter when stripping wire.

Take it further: Replace one bulb with an LED and a 220 ohm resistor and explain why the LED needs the resistor.

What it shows

A current flowing through a magnet in a magnetic field feels a sideways force (F = B I L), and here that force makes the magnet and screw spin at hundreds of revolutions per minute. It is the simplest motor that works with no coil and no commutator.

You will need

• One AA cell
• A 5 cm steel screw or nail
• A small disc neodymium magnet, 10 to 15 mm (about Rs 30 from an online shop)
• A 15 cm piece of copper wire with the insulation stripped
• A second magnet and a paper cup for the extension

Safety: The cell is shorted while the motor runs and gets hot; run it only for 10 to 20 seconds at a time. Neodymium magnets snap together hard and pinch, and small ones must be kept away from young children. Cells only.

Take it further: Build a wire homopolar motor where a bent copper loop spins around the cell instead of the magnet.

What it shows

Moving a magnet through a coil changes the magnetic flux through it and induces an emf (Faraday’s law), which lights an LED with no cell at all. Faster shaking and more turns give a brighter flash.

You will need

• A 15 cm length of PVC or a thick ballpoint pen barrel, 15 to 20 mm wide
• About 40 m of enamelled copper wire, 32 to 36 SWG (about Rs 150)
• A strong neodymium rod or stack of disc magnets that slides freely inside the tube
• Two LEDs (red works best, it needs only about 1.8 V)
• Two bottle caps or rubber stoppers to close the ends
• Tape, sandpaper and a multimeter set to AC volts

Safety: Keep neodymium magnets away from phones, cards and small children. Sand the enamel outdoors or over a bin. No cells are needed, so there is nothing to short.

Take it further: Add a diode bridge and a 1 F supercapacitor so the torch stores charge and stays lit after shaking stops.

What it shows

A solid aluminium or copper plate swinging between magnet poles stops within a few swings, while a slotted plate swings on, because circulating eddy currents are induced in the solid plate and Lenz’s law makes them oppose the motion. This is how train and roller-coaster magnetic brakes work.

You will need

• Two aluminium sheets about 8 cm by 8 cm, 1 to 2 mm thick (an old cooking pot lid or a sheet from a scrap shop); one left solid, one cut into comb slots
• Two strong neodymium block magnets or a stack of discs
• A wooden stand with a crossbar and a long bolt as a pivot
• A ruler, a protractor and a stopwatch or phone
• Glue and a small clamp

Safety: An adult must cut the slots with a hacksaw and file the edges smooth. Keep the magnets apart from each other when not fitted; they pinch fingers.

Take it further: Slide a magnet down a sloped aluminium sheet and down a slotted sheet and time both to show the same effect in a different form.

What it shows

A Wheatstone bridge is balanced when the galvanometer shows zero, and then the unknown resistance equals the known one multiplied by the ratio of the two wire lengths (X = R l / (100 minus l)). A home-built metre bridge measures resistors to within a few percent.

You will need

• A 1 m length of 28 SWG nichrome or constantan wire
• A 1.1 m wooden plank with a paper metre scale glued on
• Three brass or copper strips with screw terminals (an electrician can supply strips), or large crocodile clips
• A centre-zero galvanometer from the lab, or a multimeter on its lowest DC millivolt range
• Two AA cells, a switch and a jockey (a sharpened wire on a wooden handle)
• Known resistors: 10, 22, 47 and 100 ohm and one unmarked resistor

Safety: Cells only. Press the jockey briefly rather than sliding it, so the wire is not scraped thin. An adult must fix the terminal strips with screws.

Take it further: Measure the resistance of a coil of wire at room temperature and in hot water to find its temperature coefficient of resistance.