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Quest Comment Recommendations
ion
loop amp in 2(b)(ii) because Rf =
100 kΩ and R1 = 330 Ω were given.
Is it the non-inverting op amp in
Fig 2? But the feedback resistor
symbol was given as R2 and here it
was given as Rf.
5a Intrinsic or Extrinsic Either – (Semiconductor): Material
semiconductor? with conductivity between an insulator
and a conductor
Or – (Intrinsic semiconductor):
Insulator at absolute zero, conductor at
Typical values for resistivity of a higher temperatures
semiconductor”:
 The syllabus objective in Unit 2
Module 2 makes no explicit
mention of the “typical” values for Answer: At 300K: Semiconductor:
resistivity of a semiconductor. between 10 and 10 Ω m
-6
7
Also, these values would depend on Other Answer: Thousands of times
Temperature. greater than a conductor should be a
 Unit 2 Module 2 [AC theory and good enough answer. OR Much
Electronics] Specific Objective 2.2 larger than that for a conductor
states:
“Resistivity of semiconductors
should be compared to that of
conductors in order to place the
values in meaningful contexts”.

6b(ii)  The syllabus objective in Unit 2 Answer:
Module 3 makes no explicit  Charge is quantised. OR Charges are
mention of the “2 major whole number multiples of the basic

conclusions” made from the unit of charge.
Millikan’s oil drop experiment OR Q = Ne

 Unit 2 Module 3 [Atomic and  Value of the basic unit of charge (e)
Nuclear Physics] Specific Objective was found OR Basic unit of charge
2.5 states: was the electronic charge (e).
“describe Millikan’s oil drop

experiment; Include details of
Millikan’s experimental design”.
Specific Objective 2.6 states:
“discuss the evidence in
Millikan’s oil drop experiment for

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