• Help the next generation of students in the community for the new syllabus!
    Share your notes and exam papers on our Notes & Resources page
  • Like us on facebook here

queries about physics NESA additional sample questions (1 Viewer)

psmao

Member
Joined
May 14, 2019
Messages
89
Gender
Male
HSC
2019

question 3 in this document, shouldnt the answer be A? As
 

psmao

Member
Joined
May 14, 2019
Messages
89
Gender
Male
HSC
2019
its a question from their additional sample questions, but i think the answer is wrong or i am totally retarded lol
 

Arrowshaft

Active Member
Joined
Sep 2, 2018
Messages
549
Location
NSW
Gender
Male
HSC
2019
Well as you said, for an ideal transformer

Hence,

Now, for the galvanometer to deflect the most, the current produced has to be the highest, this only happens when is big, so either when is increased or is decreased. Hence the number of secondary coils should be decreased for the largest deflection, so B.
 

Idkwhattoput

Member
Joined
Mar 14, 2018
Messages
93
Gender
Male
HSC
2019
In this question, I get the correct graph, except it is the negative of what the answers say (answers say initially voltage is, negative but I keep getting positive). I have a feeling it has something to deal with conventional vs actual current. Does anyone know why? The reason I say induced voltage is positive is because induced current runs from the positive terminal to the negative terminal. Maybe that assumption is wrong?
 

Attachments

Arrowshaft

Active Member
Joined
Sep 2, 2018
Messages
549
Location
NSW
Gender
Male
HSC
2019
In this question, I get the correct graph, except it is the negative of what the answers say (answers say initially voltage is, negative but I keep getting positive). I have a feeling it has something to deal with conventional vs actual current. Does anyone know why? The reason I say induced voltage is positive is because induced current runs from the positive terminal to the negative terminal. Maybe that assumption is wrong?
Its because the positive current enters at the negative terminal or electrode, hence the electrode measuring ‘negative’ current so to speak, would measure positive current instead.
 

Idkwhattoput

Member
Joined
Mar 14, 2018
Messages
93
Gender
Male
HSC
2019
Its because the positive current enters at the negative terminal or electrode, hence the electrode measuring ‘negative’ current so to speak, would measure positive current instead.
So the way a voltemeter's terminals works is such that they are arrnaged oppositely to a cell/battery? I ask this because for a cell, 'negative current' ia from negative to positive, and 'postive' current is from positive to negative, but you suggest that for a voltemeter current going from the positive temrinal to the negative is actually negative current.
 

Arrowshaft

Active Member
Joined
Sep 2, 2018
Messages
549
Location
NSW
Gender
Male
HSC
2019
So the way a voltemeter's terminals works is such that they are arrnaged oppositely to a cell/battery? I ask this because for a cell, 'negative current' ia from negative to positive, and 'postive' current is from positive to negative, but you suggest that for a voltemeter current going from the positive temrinal to the negative is actually negative current.
They are not operating as a cell, they simply measure any positive or negative voltage at either end.
 

Idkwhattoput

Member
Joined
Mar 14, 2018
Messages
93
Gender
Male
HSC
2019
Actually, i get it now i think. The voltemeter's positive and negative terminals are such that they indicate the direction of current going through voltemeter rathwr than around the curcuit
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top