Physics experiments 1st unit ELECTRIC CHARGES AND FIELDS HS 2nd yr

 

1. Demonstration Experiment (Conceptual Visualization)

Title: Demonstrating Electrostatic Attraction and Repulsion

Objective: To observe the behavior of like and unlike charges.

Materials:

• Glass rod and silk cloth

• Plastic rod and fur

• Pith ball electroscope

• Thread

Procedure:

1. Rub the glass rod with silk and suspend it using a thread.

2. Rub the plastic rod with fur and bring it near the glass rod.

3. Observe the attraction or repulsion.

4. Repeat with another glass rod.

Expected Result: Like charges repel; unlike charges attract.

---

2. Quantitative Laboratory Experiment

Title: Verifying Coulomb’s Law

Objective: To verify that the electrostatic force between two point charges is inversely proportional to the square of the distance between them.

Materials:

• Coulomb torsion balance (if available)

• Two identical small charged spheres

• Ruler

• Stopwatch (optional for oscillation method)

Procedure:

1. Place two identical spheres at a known distance.

2. Measure the repulsive force using the torsion balance.

3. Vary the distance and record the change in force.

4. Plot $F$ vs $\frac{1}{r^2}$.

Expected Result: The graph should be a straight line confirming $F \propto \frac{1}{r^2}$.

---

3. Simulation-Based Experiment (Using software or online applets)

Title: Simulation of Electric Field Lines

Objective: To visualize electric field lines due to various charge configurations.

Materials:

• Computer with internet

• PhET Simulation (https://phet.colorado.edu)

Procedure:

1. Open “Charges and Fields” simulation.

2. Place single and multiple charges.

3. Observe field lines and equipotential surfaces.

4. Use sensors to measure field strength.

Expected Result: Field lines emerge from positive and enter negative charges. Field strength follows inverse square law.

---

4. Classroom Activity / Group Work

Title: Human Electroscope

Objective: To model how a gold-leaf electroscope works.

Materials:

• Paper strips or foil

• Plastic ruler

• Cloth

Procedure:

1. Rub the plastic ruler and bring it near paper strips.

2. Observe the strips repelling each other when charged.

Expected Result: Electroscope-like behavior indicating charge presence.

---

5. Inquiry-Based Experiment

Title: Investigating Conductors and Insulators

Objective: To classify materials based on their ability to conduct electric charge.

Materials:

• Battery

• Bulb holder

• Wires

• Various materials (metal, plastic, wood, rubber)

Procedure:

1. Make a simple circuit using battery and bulb.

2. Test each material by completing the circuit.

3. Record observations.

Expected Result: Conductors allow current (bulb glows); insulators do not.