Dr Pod

Question 1

What is difference between conductor , non conductor and semi conductor

Answer 1

Conductor - allows movement of charge, free electrons to carry charge e.g. metal - sea of shared electrons in solid

Non conductor - doesn’t allow movement of charge. Fixed electrons in substance e.g. plastic

Semi conductor - lies in between the above. Electrons are more fixed than in conductor but can move when certain amount of energy applied.

Question 2

Give example of a semi conductor ..

Answer 2

Diodes and thermistors use semi conductors
E.g in thermistor as temp increases, frees up electrons so they can move hence reduces resistance

Question 3

What is a galavanometer?

Answer 3

Measures small currents
Used in middle of a wheat stone bridge

Question 4

What is power (stats)

Answer 4

The ability of a study to detect a difference if there is one
1- type B error
Acceptable value is 80%
Calculated before study conducted to find out if strong enough power or if the population size needs to be increased to improve the power

Question 5

What factors increase electrical resistance

Answer 5

Temperature
- in a conductor the increase in temp will cause increase in resistance
-in a semi conductor the opposite is true

Stretching out a wire to become longer and thinner e.g strain gauge