Electric charge

Answer:

There are two types of electric charge: positive and negative.

* Like charges repel: Positive-positive and negative-negative charges repel each other.
* Opposite charges attract: Positive-negative charges attract each other.

Answer:

The balloon gaining a negative charge indicates that negatively charged particles (electrons) have been transferred from the wool sweater to the balloon. The sweater would then be positively charged.

Positively charged objects repel each other. This is because objects with the same type of charge exert a repulsive electrostatic force on each other.

The negatively charged balloon will be attracted to the positively charged wall. Unlike charges attract each other.

1. Rub the plastic rod vigorously with the cloth. (1 mark)
2. Bring the rod near small pieces of paper. If the paper is attracted to the rod, this indicates the presence of an electrostatic charge. (1 mark) Friction transfers electrons, creating a charge imbalance on the rod.

1. Attraction to small, lightweight objects (

Rubbing transfers electrons. Electrons, having a negative charge, move from the wool cloth to the plastic rod. This makes the rod negatively charged (more electrons) and the wool cloth positively charged (fewer electrons). Only electrons are transferred, not positive charges.

Electrons are transferred from the glass rod to the silk cloth. The glass rod loses negatively charged electrons, resulting in a net positive charge. The silk gains these electrons, becoming negatively charged. Only negatively charged electrons are transferred; protons do not move.

Experiment: Connect the battery, bulb, wires, and the material under test in a series circuit.
Observation: If the bulb lights, the material is a conductor. If the bulb does not light, the material is an insulator.
Explanation: Conductors allow electric current to flow, completing the circuit and lighting the bulb. Insulators resist the flow of current, preventing the bulb from lighting.

Copper Wire: The bulb will light up. This indicates that copper wire is a good conductor of electricity.
Plastic Ruler: The bulb will not light up. This indicates that the plastic ruler is an insulator and does not conduct electricity.

Conductors have many free electrons that can move easily through the material, carrying charge. Insulators have very few free electrons; their electrons are tightly bound to atoms and cannot move easily. This prevents charge flow.

Conductors: Copper, Aluminium. Insulators: Rubber, Plastic. Conductors allow electrons to flow. Insulators impede electron flow.

Answer:

Electrons and protons possess the fundamental property of charge. (1 mark)

This intrinsic charge enables them to exert electromagnetic forces on each other, attracting if opposite (electron and proton) and repelling if alike (electron and electron, proton and proton), leading to electrical phenomena. (1 mark)

An electric field is a region of space where an electric charge experiences a force. A charged particle placed in the field will experience a force; the direction of the force depends on the sign of the charge (positive or negative) and the direction of the electric field.

The electric field around a positively charged sphere is radial, directed outwards. A positive test charge placed in this field would experience a repulsive force, moving away from the sphere along a radial line.

The direction of the electric field at that point is the same as the direction of the electric force acting on the positive test charge. The electric field lines point in the direction a positive charge would move if placed in the field.

The direction of the electric field at point P is to the right. This is because the electric field direction is defined as the direction of the force on a positive charge.

The electric field lines are radial, pointing inwards towards the centre of the sphere. The field strength decreases with increasing distance from the sphere. Explanation: Electric field lines always point from positive to negative and are perpendicular to the surface of the conductor.

The electric field lines are parallel and equally spaced, indicating a uniform field strength. The electric field lines point from the positive plate to the negative plate. Explanation: Uniform field is created between plates; the direction of electric field is the direction a positive charge would be pushed.