Q.Write any five properties of cathode rays.
You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
Start your 14-day free trial to unlock the full solution →Cathode rays, discovered in low-pressure discharge tubes, are streams of fast electrons and display a set of characteristic properties — straight-line travel, negative charge, deflectability by fields, momentum, and the ability to cause fluorescence and produce X-rays.
Origin
When a high voltage is applied between two electrodes sealed in a glass tube containing gas at very low pressure, a stream of radiation is found to emanate from the cathode (negative electrode) and travel towards the anode; this radiation is called cathode rays. J.J. Thomson later established that cathode rays consist of fast-moving electrons.
Properties (any five)
-
Travel in straight lines: Cathode rays travel in straight lines from the cathode, and cast sharp, well-defined shadows of any opaque object placed in their path.
-
Negatively charged particles: They are deflected towards the positive plate when passed between two oppositely charged parallel plates, showing that they consist of negatively charged particles (electrons).
-
Deflected by magnetic fields: They are also deflected by a magnetic field, in a direction consistent with Fleming's left-hand rule for a negative charge in motion.
-
Possess momentum and kinetic energy: Cathode rays can set a small, light paddle wheel placed in their path into rotation, and can heat a metal target on which they fall — showing that they carry momentum and kinetic energy, i.e. they consist of material particles, not simply radiation.
…
Unlock everything free for 14 days
- Full step-by-step solutions
- Concept-first explanations
- Methods, shortcuts & mistakes
- PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.