Science worksheet on static electricity featuring a Van de Graaff generator and a girl with static-charged hair.

Let's solve the worksheet on Static Electricity step by step and provide clear explanations for each question.

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1. What is meant by a static charge?

Answer:
A *static charge* refers to an electric charge that builds up on the surface of an object and remains stationary (not flowing). It occurs when there is an imbalance of electrons between two objects, usually due to friction, contact, or separation. This charge stays in one place until it is discharged (e.g., through a spark or grounding).

> 🔍 Explanation: Static electricity is "static" because the charges do not move continuously like in current electricity. Instead, they accumulate on insulating materials and can cause sparks or attract small objects.

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2. Use the following diagram to answer the questions below:

The image shows a girl touching a Van de Graaff generator, which is a device that builds up a large static electric charge on its metal dome.

#### a) Explain why the girl's hair sticks out when she touches the charged Van de Graaff generator.

Answer:
When the girl touches the Van de Graaff generator, the excess electric charge (usually positive or negative) transfers to her body and then to her hair. Since each strand of hair now has the same type of charge, they repel each other due to the like charges repelling principle. This causes the hair strands to push away from each other and stand up, giving the appearance of hair sticking out.

> 🔍 Key Concept: Like charges repel — all the hairs are charged the same way, so they repel each other.

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#### b) Why is the girl probably standing on a plastic box rather than right on the floor?

Answer:
She is standing on a plastic box because plastic is an insulator, which prevents the electric charge from flowing from her body into the ground. If she were standing directly on the floor (especially if it’s conductive, like concrete or metal), the charge would flow into the Earth (grounding), and the static buildup wouldn’t occur. The plastic box insulates her, allowing the charge to remain on her body and build up.

> 🔍 Key Concept: Insulators block the flow of electricity; conductors allow it. To maintain static charge, you need insulation from the ground.

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#### c) What might happen if the girl got her left hand close to a water tap or other grounded object?

Answer:
If the girl brought her left hand close to a water tap or another grounded object, a spark might jump from her hand to the object. This happens because the excess charge on her body wants to flow to the ground (which is neutral and can accept charge). The air breaks down as the electric field becomes strong enough, allowing a sudden discharge — a visible spark.

> 🔍 Why this happens: The grounded object provides a path for the charge to flow back to the Earth, releasing the built-up static energy. This is similar to how lightning occurs — a rapid discharge between charged and neutral regions.

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✔ Summary of Key Concepts:

- Static charge: Imbalance of electrons that doesn't flow.
- Like charges repel: Explains hair standing up.
- Insulators prevent grounding: Plastic box keeps charge on the person.
- Grounding discharges static: Spark occurs when charge flows to Earth.

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This worksheet helps students understand real-world examples of static electricity, including charge transfer, insulation, and discharge phenomena.