Electricity and Circuits Test - 7

The electrical conductivity of matter is dependent upon the atomic structure of the material from which the conductor is made. In any solid material, such as copper, the atoms which make up the molecular structure are bound firmly together. At room temperature, copper will contain a considerable amount of heat energy. Since heat energy is one method of removing electrons from their orbits, copper will contain many free electrons that can move from atom to atom. When not under the influence of an external force, these electrons move in a zigzag manner within the conductor. This movement is equal in all directions so that electrons are not lost or gained by any part of the conductor. When controlled by an external force, the electrons move generally in the same direction. The effect of this movement is felt almost instantly from one end of the conductor to the other. This electron movement is called an ELECTRIC CURRENT.
Some metals are better conductors of electricity than others. Silver, copper, gold, and aluminum are materials with many free electrons and make good conductors. Silver is the best conductor, followed by copper, gold, and aluminum. Copper is used more often than silver because of cost. Aluminum is used where weight is a major consideration, such as in high-tension power lines, with long spans between supports. Gold is used where oxidation or corrosion is a consideration and a good conductivity is required.
Hence, copper is a good conductor of electricity.

Silk does not allow electric current to pass through it.

Electrical charge can be transferred from one object to another object through conductors. because conductors have free electrons that carry charges from one object to another object. whereas In insulators, they do not have free electrons so they can't transport charges exp: Air. Vacuums have no medium so it also behaves like insulators, therefore, they will not transfer charge. 

Copper wire being a conductor can conduct .

The connection wires are made of copper. 
Copper is a good conductor of electricity as it allows the electricity to flow through it easily. Copper as a connecting wire has very low electrical  resistance. Copper combines several properties that have traditionally made it preferred for most electrical wiring. It provides good contact surface, is ductile (is easily bent repeatedly without breaking) and it is not very expensive and is easy to manufacture.

Copper and aluminium offer a low resistance to the flow of current and hence they are good conductors of electricity. Copper and aluminium are highly ductile and hence can be used for preparing the wire. Copper being more ductile, it is used in making thin wires, and aluminium is used for making thicker wires. Thus, they are suitable for making wires used in electrical circuit.
Hence, the statement is true.

Any charged object - positive or negative, conductor or insulator - creates an electric field that permeates the space surrounding it.  So charges are on the outer surface of the conductor.

Also, since conductors allow electrons to be transported from particle to particle, a conductor always distribute its charge until the overall repulsive forces between the excess electrons is minimized. Hence no charge inside the conductor.

Batteries convert chemical energy into electricity. Batteries are made up of one or more separate sections, or cells, containing a chemical called an electrolyte. 
Each cell has two electrically conductive electrodes immersed into its electrolyte. The electrodes are made of different materials; one releases electrons into the electrolyte, and the other absorbs them. 
When an electrical device is connected to the electrodes, an electrical current flows through it and provides electric power for its operation. 
Hence,  The energy stored in the dry cell is in the form of chemical energy.

$$\textbf{Correct option: Option (B).}$$

$$\textbf{Explanation:}$$

Insulators have tightly bound electrons which cannot move freely and hence cannot conduct electricity.

$$\textbf{Thus, option (B) is correct.}$$