When an electric current flows through a conductor (like a wire), it produces a magnetic field around it. This is called the magnetic effect of electric current.
Key Concepts:
- Magnetic Field Around a Wire:-
- Current in a wire produces a magnetic field.
- Right-Hand Thumb Rule helps determine the direction of the field.
- Solenoid:-
- A coil of wire that creates a strong magnetic field when current flows through it. It behaves like a magnet.
- Electromagnet:-
- A temporary magnet created by passing current through a coil around an iron core.
- Force on a Current-Carrying Conductor: -
- A wire carrying current in a magnetic field experiences a force.
- Fleming's Left-Hand Rule determines the direction of the force.
Applications:
- Electric Motors:Use the force on current-carrying conductors in a magnetic field to produce motion.
- Electromagnets:Used in devices like cranes to lift heavy magnetic materials.
Practice Questions PDF
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Questions on Magnetic Effects of Electric Current
Showing 61–90 of 21561.A conductor is moved in a magnetic field. In which direction must it be moved to induce maximum current? 62.What is the function of slip rings in an AC generator? 63.Explain the difference between AC and DC current generated by a generator. 64.A generator converts mechanical energy into electrical energy. What is the fundamental principle behind its operation? 65.How can the speed of rotation of a DC electric motor be increased? 66.Why are the field lines inside a current-carrying solenoid nearly parallel to each other? 67.Describe the role of a split-ring commutator in a DC electric motor. 68.An electric motor converts electrical energy into mechanical energy. On what principle does it work? 69.Consider a current loop placed in a uniform magnetic field. Under what conditions will the loop experience a net force? 70.A coil of insulated wire is wound around a cylindrical cardboard tube. Will it behave as an electromagnet? Justify your answer. 71.Why is soft iron used as the core of an electromagnet, rather than steel? 72.A conductor is placed perpendicular to a magnetic field and a current is passed through it. If the direction of the current is reversed, what happens to the direction of the force experienced by the conductor? 73.A charged particle enters a uniform magnetic field at an angle to the field lines. Describe the path of the particle and explain the force acting on it. 74.How does the strength of the magnetic field inside a current-carrying solenoid change if the number of turns per unit length is doubled, keeping the current constant? 75.Two parallel wires carry current in the same direction. What type of force exists between them, and why? 76.A student observes that a current-carrying solenoid, when suspended freely, aligns itself in a particular direction. Explain why this phenomenon occurs. 77.A compass needle is placed near a current-carrying straight conductor. If the direction of current in the conductor is reversed, what will be the effect on the compass needle? 78.Which of the following is a key application where temporary magnetism is crucial? 79.A compass needle deflects when brought near a current-carrying wire because: 80.The force between two parallel current-carrying wires depends on: 81.What material is typically used to insulate the wire in an electromagnet coil? 82.The region where magnetic field lines are closest together indicates: 83.Which animal uses Earth's magnetic field for navigation? 84.A simple electric bell uses an electromagnet to: 85.If you reverse the battery terminals connected to an electromagnet, what happens? 86.The magnetic poles always exist in: 87.Why are electromagnets preferred over permanent magnets in devices like magnetic separation machines? 88.How does the Earth's magnetic field protect us? 89.The magnetic field produced by a current-carrying wire is directly proportional to the: 90.Which effect of electric current is responsible for the working of an electric fan?