The electrons in the beam of a television tube move horizontally from South to North. The vertical component of the earth's magnetic field points down. The electron is deflected towards _____

CONCEPT:

• Fleming Left-hand rule gives the force experienced by a charged particle moving in a magnetic field or a current-carrying wire placed in a magnetic field.
• It states that "stretch the thumb, the forefinger, and the central finger of the left hand so that they are mutually perpendicular to each other.
• If the forefinger points in the direction of the magnetic field, the central finger points in the direction of motion of charge, then the thumb points in the direction of force experienced by positively charged particles."

• The magnitude of the force is given by 

⇒ F = I(L × B)

Where I = Amount of current flowing through the conductor, B =  Magnetic field, and L = Length of conductor

EXPLANATION:

• Given that electrons in the beam of a television tube move horizontally from South to North that means current (I) is flowing from North to South.
• The vertical component of the earth's magnetic field points down, which means it is acting in the eastern direction.
• Hence the electrons are deflected toward the West. Therefore option 1 is correct.