The question asks for the most suitable material for the core of an electromagnet. An electromagnet needs to be easily magnetized when current flows and easily demagnetized when the current is switched off. This property is related to the material's magnetic permeability and retentivity.
Correct Option: C) Soft iron is the most suitable material for making the core of an electromagnet because it has high magnetic permeability, allowing it to be easily magnetized, and low retentivity and coercivity, ensuring it can be easily demagnetized when the current is switched off.
This question tests knowledge about magnetic properties of different materials. Materials are classified based on how they interact with a magnetic field. The key is to identify which of the given options is a non-magnetic material.
Correct Option: C) Brass is an alloy of copper and zinc, neither of which is ferromagnetic. Therefore, brass is not attracted by a magnet.
The question asks about the direction of magnetic field lines. Understanding the conventional representation of magnetic field lines around a magnet is key to answering this question.
Correct Option: A) N-pole and end on S-pole
This option correctly describes the conventional direction of magnetic field lines outside a magnet, where they are considered to emerge from the North pole and converge at the South pole.
This question tests the understanding of how magnetic materials interact with an external magnetic field, specifically within a solenoid. When a soft iron bar is introduced into a current-carrying solenoid, it gets magnetized, and its induced magnetic field adds to the original field of the solenoid.
B) Will increase - When a soft iron bar (a ferromagnetic material) is placed inside a current-carrying solenoid, it gets strongly magnetized in the direction of the solenoid's magnetic field. This induced magnetic field adds to the original field of the solenoid, resulting in a significant increase in the total magnetic field inside.
The question asks about the rule used to determine the direction of force on a current-carrying conductor placed in a magnetic field. This is a fundamental concept in electromagnetism, specifically related to the motor effect.
A) Fleming’s left hand rule is used to determine the direction of force on a current-carrying conductor in a magnetic field. This rule is crucial for understanding the working principle of electric motors.
This question asks about the rule used to determine the direction of induced current. This concept is fundamental to electromagnetic induction.
A) Fleming’s right hand rule is used to determine the direction of the induced current in a conductor moving in a magnetic field. It is crucial for understanding the working principle of electrical generators.