Which of the following can form a closed circuit and light up the bulb?, A. Batteries + loose wires + bulb, B. Correctly connected batteries + wires + bulb + closed switch, C. Batteries (reverse polarity) + wires + bulb, D. Broken wire + batteries + bulb, Which object is a good insulator?, A. Metal fork, B. Aluminium foil, C. Rubber eraser, D. Paper clip, How does a switch turn off a bulb?, A. It breaks the circuit (opens it), B. It blocks the batteries’ power, C. It melts the wire, D. It damages the bulb, Why are power cable jackets made of plastic?, A. Plastic is a conductor to carry electricity, B. Plastic is cheap and easy to make, C. Plastic is an insulator to prevent electric shocks, D. Plastic is flexible for bending, What should you do FIRST if your friend gets an electric shock from a socket?, A. Touch them to pull them away, B. Cut off the power supply, C. Call 999 immediately, D. Use your bare hand to turn off the switch, Tap water is an insulator, so it’s safe to touch switches with wet hands., True, False, A bulb can light up in an open circuit if the batteries are new. (, True, False, Overloading a socket (connecting too many appliances) is dangerous because it may cause overheating., True, False, Pencil lead is a conductor because it’s made of metal., True, False, A student builds a circuit with 2 batteries (correctly connected), a bulb, wires, and a switch. The bulb lights up when the switch is closed but dims slightly when another identical bulb is added in the same circuit. Why does the bulb dim?, A. The second bulb is an insulator, B. The total electricity from the batteries is shared between two bulbs, C. The switch is damaged by the extra bulb, D. The circuit becomes an open circuit with two bulbs, Which of the following statements about conductors and insulators is completely correct?, A. All metals are conductors, and all non-metals are insulators, B. Conductors block electricity, while insulators allow it to flow, C. Graphite (pencil lead) is a non-metal but acts as a conductor, D. Plastic is a conductor, so it’s used for cable inner wires, Why is it dangerous to use a portable electric heater in a bathroom?, A. Bathrooms are too small for heaters, B. Humidity in bathrooms makes insulators become conductors, C. Tap water and moist air are conductors, increasing electric shock risk, D. Heaters use too much electricity, overloading bathroom sockets, A circuit diagram shows a battery (positive pole connected to wire), a bulb, a broken wire, and a switch. What will happen if the broken wire is replaced with a wooden stick and the switch is closed?, A. The bulb lights up brightly, B. The bulb dims but stays on, C. The bulb does not light up (circuit remains open), D. The battery overheats, Which step is critical but often forgotten when helping someone with an electric shock?, A. Calling 999 before separating the victim from power, B. Using an insulator to disconnect the victim from the power source, C. Checking if the victim is breathing before turning off power, D. Wiping the victim’s hands dry to stop the shock, A bulb will light up if it’s connected to a battery with wires, even if the switch is open.A bulb will light up if it’s connected to a battery with wires, even if the switch is open., True, False, Rubber gloves are safe to use when handling electrical appliances because rubber is a conductor that absorbs electricity, True, False, If a power cable’s plastic jacket is damaged but the inner metal wire is not broken, it’s still safe to use the appliance.If a power cable’s plastic jacket is damaged but the inner metal wire is not broken, it’s still safe to use the appliance., True, False, Adding more batteries (correctly connected in series) to a simple circuit will make the bulb brighter because more electricity flows through it., True, False

Closed circuit

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