8/18/2019 Definations Physics

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Real Image  image can be formed on a screen OR is formed by rays of light meeting

Virtual image cannot be formed on a screen/rays diverge away from the image/do not meet to

form image

Parallel connection  Each appliance is connected across same voltage supply

100 % efficient transformer no/very little energy/power lost or energy/power in =

energy/power out

Describe how a voltage across the primary coil causes a voltage across the secondary coil.

a.c./changing current (in primary) magnetic flux/field/force in core

alternating/changing magnetic field

field cuts secondary changing flux linage in (secondary) induces emf/current in (secondary)

!tate two reasons why it is cheaper to transmit electrical energy at high voltage.

less heat/energy/power loss

thinner/smaller cables "less metal used " less massive pylons" ignore less electricity loss

electric field  force is produced on any charge placed in the field