Problem 25 - Arihant AIEEE Physics

Question

Two bodies \(A\) and \(B\) of definite shape are placed near one another. Electrostatic attraction is found between thebodies, then: (a) both bodies must be positively charged (b) both bodies must be negatively charged (c) both bodies must be oppositely charged (d) body \(A\) may be neutral

Step-by-Step Solution

Answer

(c) and (d) are correct.

Step 1: Understanding Attraction

In electrostatics, opposite charges attract each other while like charges repel each other. If there is an attraction between two objects, they must have opposite charges or one of them could be neutral since a charged object can also attract a neutral one.

Step 2: Analyzing the Options

Let's evaluate the options: (a) and (b) suggest like charges. However, like charges repel each other, not attract. (c) implies opposite charges, which cause attraction. Option (d) considers one body being neutral; charged bodies can indeed attract neutral ones.

Step 3: Verifying Attraction Possibilities

Since the attraction is noticed, options indicating the presence of opposite charges or a scenario where a charged object attracts a neutral one are valid. Therefore, options (c) and (d) are possible.

Step 4: Choosing the Correct Answers

Based on the analysis, attraction can occur when two bodies have opposite charges or one body is neutral with the other charged. Consequently, both options (c) and (d) are correct.

Key Concepts

Electrostatic Attraction

When we talk about electrostatic attraction, we're referring to the force that causes charged objects to pull towards each other. This is a key concept in studying interactions between electric charges. If you've ever felt a slight tug when bringing a balloon near your hair after rubbing it on fabric, you've experienced electrostatic attraction firsthand.

This force is fundamental because it explains why certain materials stick together and others repel each other. For instance:

• An electron, with a negative charge, is attracted to a proton, which has a positive charge.
• Objects with opposite charges will attract each other.

Because of this natural tendency, electrostatic attraction plays a crucial role in various scientific and everyday phenomena, from holding atoms and molecules together to things like static cling in clothes.

Opposite Charges

The principle of opposite charges is at the heart of electrostatic attraction. This concept follows a simple rule: opposites attract. That means if one object is positively charged, and another is negatively charged, they will pull towards one another.

Charges come in two types:

• Positive charges, often due to a deficiency of electrons.
• Negative charges, usually because of an excess of electrons.

In electrostatics, the interaction between these charges is predictable. This predictability allows scientists to use the concept of opposite charges to explain and even control the movement of electrical energy in circuits and devices.

Charged and Neutral Objects

Interestingly, the interaction between charged and neutral objects also results in electrostatic attraction. A neutral object has an equal number of protons and electrons, so it doesn't have an overall charge.

However, a charged object can still attract a neutral one. How does this happen? It occurs due to a process called polarization. When a charged object is brought close to a neutral object, it can cause the charges within the neutral object to redistribute slightly, creating an imbalance. This redistribution can induce a temporary opposite surface charge which leads to attraction.

• For example, a charged balloon can stick to a neutral wall because of the redistribution of charges in the wall.

Thus, the ability of charged objects to attract neutrals is yet another fascinating aspect of electrostatics.