In a cathode ray tube, why do $e-$ (electrons) move from the negative end (cathode) to the positive end (anode)?

• A. Because the pressure difference inside the tube pushes $e-$ toward the anode.
• B. Because $e-$ are negatively charged and are attracted to the positive anode due to the electric field.
• C. Because $e-$ move randomly and sometimes end up at the anode by chance.
• D. Because $e-$ are positively charged and are repelled by the negative cathode.

Answer: (B)

Verified step by step guidance

1. Understand that electrons (e⁻) carry a negative electric charge.
2. Recognize that in a cathode ray tube, the cathode is negatively charged and the anode is positively charged, creating an electric field inside the tube.
3. Recall that electric fields exert forces on charged particles: negatively charged electrons experience a force directed opposite to the electric field lines, which point from positive to negative.
4. Therefore, electrons are attracted toward the positive anode and repelled by the negative cathode due to the electric force.
5. Conclude that the movement of electrons from the cathode to the anode is caused by this electric attraction, not by pressure differences or random motion.