CBSE
CLASS 10 SCIENCE
CHAPTER13:MAGNETIC EFFECTS OF ELECTRIC CURRENT
NOTES
➢Introduction:
👉Magnetism and electricity are closely related phenomena.
👉Hans Christian Oersted discovered in 1820 that an electric current flowing through a wire produces a magnetic field around it.
👉This chapter focuses on the magnetic effects of electric current and their applications.
1. Magnetic Field and Magnetic Field Lines:
👉A magnetic field is the region around a magnet or a current-carrying conductor where its magnetic influence can be felt.
👉The direction of a magnetic field is from the north pole to the south pole of a magnet.
👉Magnetic field lines are used to represent the direction and strength of the magnetic field.
👉The magnetic field lines are closer together where the field is stronger and farther apart where it is weaker.
2. Magnetic Field Due to a Current-Carrying Conductor:
👉When an electric current flows through a straight conductor, a circular magnetic field is produced around the conductor.
👉The direction of the magnetic field can be determined using the right-hand thumb rule.
👉Right-hand Thumb Rule: If the right hand is wrapped around the conductor with the thumb pointing in the direction of the current, the curled fingers indicate the direction of the magnetic field.
3. Fleming's Right-hand Rule:
👉Fleming's right-hand rule is used to determine the direction of induced current or the motion of a conductor in a magnetic field.
4. When the thumb, index finger, and middle finger of the right hand are held perpendicular to each other:
👉Thumb: Points in the direction of motion (or induced current).
👉Index Finger: Points in the direction of the magnetic field.
👉Middle Finger: Points in the direction of the induced current (or motion).
5. Fleming's Left-hand Rule:
👉Fleming's left-hand rule is used to determine the direction of the force experienced by a current-carrying conductor in a magnetic field.
👉When the thumb, index finger, and middle finger of the left hand are held perpendicular to each other:
👉Thumb: Points in the direction of the force.
👉Index Finger: Points in the direction of the magnetic field.
👉Middle Finger: Points in the direction of the current.
6. Magnetic Field due to a Current Through a Circular Loop:
👉When an electric current flows through a circular loop, it produces a magnetic field in the surrounding space.
👉The direction of the magnetic field can be determined using the right-hand thumb rule.
👉Right-hand Thumb Rule: Imagine holding the circular loop with your right hand such that your fingers encircle the loop in the direction of the current. Your extended thumb will then point in the direction of the magnetic field inside the loop.
7. Thumb Rule for Magnetic Field Around a Solenoid:
👉The thumb rule is used to determine the direction of the magnetic field around a current-carrying solenoid.
👉If the fingers of the right hand are wrapped around the solenoid in the direction of the current, the thumb points in the direction of the magnetic field inside the solenoid.
⭐Remember, these rules are used to determine the direction of various quantities (current, force, magnetic field) in relation to each other in the context of the magnetic effects of electric current. It's essential to practice and understand these rules thoroughly to apply them effectively.
