Question

If a student rubs a glass rod with a piece of silk, giving the rod a positive charge, which of the items will the rod attract?
A.
Balloon 1 and Plastic sheet 2


B.
Balloon 2 and Plastic sheet 1


C.
Plastic sheet 1, only


D.
Balloon 1, only

Answer 1

To determine which items the positively charged glass rod will attract, we need to consider the concept of charge types. A positively charged object will attract negatively charged objects and neutral objects.

Since the glass rod becomes positively charged when rubbed with silk, it will attract:

1. Any negatively charged objects (which are typically made from plastic).
2. Neutral objects, since they can become polarized in the presence of a charged object.

Now, let's analyze the options provided based on typical charging characteristics of balloons and plastic sheets:

- **Balloon 1 and Balloon 2:** Balloons are commonly made of rubber, which can be negatively charged when rubbed against other materials. Thus, a positively charged rod could attract either balloon if they have gained a negative charge.
- **Plastic sheet 1:** This could also become negatively charged depending on the material it is rubbed against, making it attractive to the positively charged rod.
- **Plastic sheet 2:** Similar reasoning as above.

Without more specific details on how each object is charged or could be charged, a reasonable assumption can be made based on common knowledge.

Therefore, if the question does not specify the charge of each item, we can conclude:

- **Choose the option describing all items that could potentially be negatively charged or neutral.**

Based on typical scenarios:

**A: Balloon 1 and Plastic sheet 2** is likely a safe assumption, as both could have negative charges.

However, if Plastic sheet 1 is explicitly known to be neutral or charged negatively, then it would also attract the rod.

Thus, if you have to select an option without specifics on the charge states of the plastic sheets and balloons, most answers including at least one negatively charged item would be good, leaning towards **C and A** based on the maximization of potential attraction.

If you choose the most broadly inclusive and likely options: **A. Balloon 1 and Plastic sheet 2** would be a solid choice.