Electric Circuits: 28 MCQs with answers

Electric cell

An electric cell is a portable source of electrical energy, as stated in the chapter.

positive, negative

The metal cap is the positive terminal and the metal disc is the negative terminal of an electric cell.

battery

When two or more cells are connected together, it is called a battery.

negative

The lamp glows when the positive terminal of one cell is connected to the negative terminal of the next cell.

filament

The thin wire inside the glass bulb that glows is the filament.

positive

The longer wire of an LED is the positive terminal, and the shorter wire is the negative terminal.

Key

Metals like keys are conductors, while plastic, wood, and rubber are insulators.

An electric cell

An electric cell is a portable source of electrical energy, as stated in the content. The switch controls the circuit, wires connect components, and an LED is a device that uses energy.

positive; negative

The content states that an electric cell has a positive terminal (the metal cap) and a negative terminal (the flat metal disc).

Copper

Copper is a metal and a good conductor. Plastic, rubber, and glass are insulators that do not allow current to flow easily.

battery

The content defines a battery as a combination of two or more cells connected together. A switch controls the circuit, a circuit is the path, and a filament is part of an incandescent lamp.

negative

The content states that in a battery, the positive of one cell connects to the negative of the next. This is how cells are arranged in a torch.

LED lamp

The content explicitly states that an LED lamp has no filament; it uses a semiconductor. Incandescent lamps and torch bulbs contain filaments.

filament

The content says that an incandescent lamp contains a thin filament that glows when current passes through it. Terminals are on cells, a switch controls the circuit, and a conductor is a material.

To protect us from electric shocks

The content states that wires are covered with plastic or rubber, which are insulators, to protect us from shocks. It does not improve conductivity or current flow.

positive; negative

By convention, current flows from the positive terminal to the negative terminal, as stated in the content.

one

The content says an LED allows current to pass in only one direction, so it glows only when current flows in that specific direction.

LED lamp

LEDs do not have filaments; they have two terminals with one longer wire (positive) and one shorter wire (negative).

one

Current can pass through an LED in one direction only, so it glows only when connected correctly.

positive, negative

The direction of electric current is conventionally from the positive to the negative terminal of the cell.

Copper

Copper is mainly used for electrical wires because it is a good conductor, comparatively cheaper, and abundant.

To protect people from electric shocks

Plastic and rubber are insulators, so they cover wires to protect people from electric shocks.

open

When the switch is off, there is a gap in the circuit, making it open and preventing current flow.

A switch is the source of electric current in a circuit.

A switch is not a source of current; it only completes or breaks the circuit.

symbols

A circuit diagram uses standard symbols to represent components, making it easier to understand.

positive

In the symbol for an electric cell, the long line represents the positive terminal and the short line represents the negative terminal.

True

For an incandescent lamp, it does not matter which terminal connects to positive or negative; it glows as long as the circuit is complete.

False

An LED glows only when its positive terminal (longer wire) is connected to the positive terminal of the battery and negative to negative.