Radio And TV Flashcards
What are electric field lines?
Move from positive to negative charges, charged particles experience a force along field lines
What is a monopole?
Electric field induced by electric charge
What is a dipole?
Magnet creates magnetic field
How does an antenna work?
Charge moves up and down producing a polarised electric field in the vertical direction which induces a magnetic field in the horizontal direction
What is an inductor?
A coil that creates a magnetic field by storing energy
What is a capacitor?
Stores electric charges in the form of energy
How does a radio transmitrer-reciever work?
Electric charge oscillates draining tank circuit in ine side and charge oscillates feeding tank on other side
How does a cathode ray tube work?
- Electrons emitted
- Electrons selected by grid
- Accelerated by anode
- Focused by focusing coil
- Vent by deflecting coil
How does an electron gun work?
- Electrons emitted by cathode
- Changing grid voltage changes beam intensity
- Focusing coil focuses electrons on phosphor screen
Which direction does a charge particle experience force when travelling through a magnetic field?
Perpendicular to both the field and the motion of the charge
What is a phosphor screen?
It glows when struck by electrons
