Electric Current & its Effects - UPSC Sci Tech Free MCQ Test with solutions

A circuit breaker can be reused multiple times. It typically consists of a simple switch connected to an electromagnet.

Electrical current needs a closed path, or circuit, to flow. When the switch is off, the current does not flow. A switch can either prevent or allow the current to flow through it.

An electric fuse is a safety device used to prevent electrical circuits from overheating and causing fires. It acts like a barrier that breaks the circuit if the current exceeds a safe limit, protecting the wires and devices.

• In an electric cell symbol, the longer line indicates the positive terminal.
• The shorter line represents the negative terminal.
• This distinction is crucial as it shows the direction of current flow, which moves from positive to negative.
• Understanding this helps in correctly connecting cells in circuits.
• This standard notation is widely used in electrical diagrams and schematics.

When a compass needle is placed near a current-carrying wire, it will experience a magnetic field created by the electric current flowing through the wire. This magnetic field interacts with the magnetic field of the compass, causing the needle to deflect from its usual north-south alignment. The direction of the deflection depends on the direction of the current in the wire and the orientation of the compass.

When two cells are joined together via connecting wires in such a way that the positive end of one cell is joined the negative end of another cell. This arrangement is called a battery. Thus, a battery is a combination of two or more cells.

An electromagnet is formed when electric current flows through a wire coil, generating a magnetic field. Unlike a permanent magnet, it can be turned on or off by controlling the current.

There is a thin filament present inside a bulb that glows and produces light. If filament of bulb gets broken, electric current will not flow through the bulb and it will not glow.

The correct answer is Iron. An electromagnet is a device consisting of a core of magnetic material surrounded by a coil, through which an electric current is passed to magnetize the core. An electromagnet is attracted by Iron. An electromagnet is used wherever controllable magnets are required.

Hans Christian Oersted was the first person to notice the deflection of compass needle every time the current was passed through the wire kept near it.