Important Questions: Chemical Effects of Electric Current - Class 8 MCQ

Current is the flow of charge.

In electrolytic solutions, electrolyte splits into positive and negative ions. The charge is moved through ions.

Insulators are substances that do not conduct electricity.

Wood is an insulator while iron, graphite and silver are good conductors of electricity.

An LED has two leads. One lead is slightly longer than the other. The longer lead is always connected to a positive terminal of the battery while the shorter lead is always connected to a negative terminal of the battery. In circuit (B) switch is present and is in its ON position. Only this makes the LED glow.

In a cell, chemical energy is converted into electrical energy.

The characteristic of an electrolyte is that it should be able to form positive and negative ions.

Citric acid is present in the lemon juice which acts as an electrolyte.

The electrolyte in a dry cell is ammonium chloride.

In a dry cell, metal cap on the carbon rod acts as a positive terminal.

The common dry cell produces a voltage of 1.5 V

When electric current flows through a conductor, some amount of electrical energy is converted into heat energy.

Nichrome is an alloy of nickel and chromium.

Electrolysis is the splitting of a compound using electricity.

Due to the heating effect of current, the filament of the bulb gets heated to a high temperature and it starts glowing.

LEDs are extensively used to replace bulbs because they consume less electricity, have longer life and have more power.

Sea water is saline and so, it is a good conductor of electricity.

Magnetic effect of current is responsible for the deflection of a compass needle in an electric field.

Electroplating is the most common industrial application of chemical effects of electric current as are galvanizing and anodizing.

Distilled water or pure water is a bad conductor of electricity.