Magnetic Force

To solve the problem, we need to understand what the curled fingers of the right hand represent in the Right Hand Thumb Rule.

1. Understanding the Right Hand Thumb Rule:
According to the Right Hand Thumb Rule, if the thumb of your right hand points in the direction of the current in a straight conductor, then the direction in which your fingers curl represents the direction of the magnetic field lines around the conductor.

2. Application of the Rule:
- Thumb → Direction of current
- Curled fingers → Circular magnetic field lines

3. Elimination of Other Options:
- Resistance is not indicated by this rule
- Direction of induced emf is related to Faraday’s law and Fleming’s right hand rule
- "None of these" is incorrect since the correct answer is option 1

Final Answer:
The curled fingers represent the Direction of magnetic field.

To solve the problem, we need to determine the magnetic force acting on a current-carrying wire placed perpendicular to a magnetic field.

1. Understanding the Formula:
The magnetic force on a current-carrying conductor placed in a uniform magnetic field is given by:


where:
= magnetic field strength
= current
= length of the conductor in the magnetic field
= angle between the wire and the magnetic field

2. Given Condition:
The wire is oriented perpendicular to the magnetic field, so:

3. Substituting in the Formula:

Final Answer:
The magnetic force is .

To solve the problem, we need to understand how a solenoid behaves when electric current flows through it.

1. Magnetic Field of a Solenoid:
A solenoid is a coil of wire. When electric current passes through it, it produces a magnetic field similar to that of a bar magnet.
- One end of the solenoid acts like a north pole.
- The other end acts like a south pole.
The magnetic field inside the solenoid is uniform and parallel to its axis, just like the field inside a bar magnet.

2. Comparison with Given Options:
- Bar magnet: ✔ Matches the behavior of a solenoid.
- Horse shoe magnet: Has a different field structure.
- Insulator: Does not produce a magnetic field.
- Steel rod: A solid metal, not associated with magnetic field generation unless magnetized.

Final Answer:
An electric current carrying solenoid behaves like a