Problem 6 - Arihant AIEEE Physics

Question

A sure test of electrification is: (a) attraction (b) repulsion (c) friction (d) induction

Step-by-Step Solution

Answer

The sure test of electrification is repulsion (b).

Step 1: Understanding Electrification Tests

In physics, electrification refers to a body's ability to exhibit attractive or repulsive forces due to charge. A test of electrification verifies whether an object has an electric charge.

Step 2: Exploring Options

Let's analyze each option to understand what kind of interaction it refers to: - (a) Attraction: A charged body can attract both neutral and oppositely charged objects. - (b) Repulsion: A charged body will only repel another charged body with the same type of charge. - (c) Friction: This is a method to induce charge, not a test of electrification. - (d) Induction: Practice of generating charge without contact; it's more for inducing charge, not testing.

Step 3: Effectiveness of Repulsion

Repulsion is a definitive test for electrification because only like charges repel. If there's repulsion between two objects, both must be charged. This confirms electrification.

Step 4: Conclusion

Based on the analysis, option (b) Repulsion is the surest test of electrification as it only occurs between similarly charged bodies, certifying that both bodies are charged.

Key Concepts

Attractive and Repulsive Forces

Attractive and repulsive forces are essential concepts in the study of electric charges. When objects become charged, they exhibit these forces depending on the nature of their charges.
An attractive force occurs when two objects with opposite charges come close to each other. For instance, a positively charged object will attract a negatively charged object. This attraction occurs because opposite charges exert force towards each other.
On the other hand, repulsive forces occur when two similarly charged objects interact. For example, two positively charged objects will push away from one another just as two negatively charged objects would. This happens because like charges exert force away from each other.
In the context of determining electrification, repulsion is a more reliable indicator because if two objects repel each other, they must be similarly charged, confirming the presence of charge.

Electric Charge

Understanding electric charge is fundamental in physics. Electric charge is a property of matter that causes it to experience a force when placed in an electromagnetic field. There are two types of charges: positive and negative.
Electric charge is measured in coulombs (C) and is carried by particles, such as electrons, which have a negative charge, and protons, which have a positive charge. An object becomes charged through the imbalanced presence of these charged particles.
Here are a few key points about electric charge:

• Like charges repel each other.
• Opposite charges attract each other.
• Charge can be transferred from one object to another.

When an object has an equal number of protons and electrons, it is neutral. But when this balance is disturbed, the object becomes an electrically charged, giving rise to attraction or repulsion forces.

Methods of Charging

There are several methods through which objects can become charged. Each method involves the transfer or induction of electric charge.
Here are the three primary methods of charging:

• Friction: This involves rubbing two different materials together, leading to the transfer of electrons from one material to the other. For example, rubbing a balloon against your hair can cause the balloon to become negatively charged.
• Conduction: Charging by conduction occurs when a charged object comes into contact with a neutral object. The charge is transferred, resulting in both objects sharing the overall charge.
• Induction: This method involves bringing a charged object close to a neutral object without touching it. The presence of the charged object causes a redistribution of charges within the neutral object, effectively charging it by inducing a charge separation.

Each of these methods plays a significant role in how we understand and demonstrate electrification in practice, allowing us to manipulate and observe electrical phenomena.