Life'sHard
Well-Known Member
- Joined
- May 24, 2021
- Messages
- 1,101
- Gender
- Male
- HSC
- 2021
- Uni Grad
- 2025
Thanks for the clarificationAll of those questions are from the North Sydney Girls High School 2020 Physics Trial Examination.
Thanks for the clarificationAll of those questions are from the North Sydney Girls High School 2020 Physics Trial Examination.
Confusingly, the NSBHS physics paper I actually thought was terrible, so I would assume the same from NSGHS, so it seems they're not under the same administrations.NSGHS has some really good questions in its maths exams so I am not surprised that the same is true of their physics exams. Definitely a source worth trying.
I wondered whether to make any comment on NSBHS v NSGHS exams, but decided not to, but since you have brought it up...Confusingly, the NSBHS physics paper I actually thought was terrible, so I would assume the same from NSGHS, so it seems they're not under the same administrations.
Pre sure it's
For Q1, I'm a little laggy havent done phys in a while, how do you determine force when the N and S poles arent given? Also what's Icm?Pre sure it's
Q1)d - solenoid rule and then force on each side
Q2)b - look at difference in mass 2.5g is divisible by all of them
Q3)c - lcm
Use the right hand solenoid rule on both sides to determine the polesFor Q1, I'm a little laggy havent done phys in a while, how do you determine force when the N and S poles arent given? Alos what is Icm?
Hmm is the direction of grip the direction of rotation? Where the thumb is the direction of current.Use the right hand solenoid rule on both sides to determine the poles
and lcm = lowest common multiple
fingers are current and thumb points toward north poleHmm is the direction of grip the direction of rotation? Where the thumb is the direction of current.
q1 is a decent q. where r u getting this from?
I'm cooked man what? I can't seem to use the rule in relation to the the flow of current for the diagram. How would your curled fingers mimic the direction of flow in the motor?fingers are current and thumb points toward north pole
Sydney Boysq1 is a decent q. where r u getting this from?
pre sure q1 is hscq1 is a decent q. where r u getting this from?
curl ur fingers in direction of currentI'm cooked man what? I can't seem to use the rule in relation to the the flow of current for the diagram. How would your curled fingers mimic the direction of flow in the motor?
Sydney Boys
don't use it on the actual DC motor coil (drawn in bold).I'm cooked man what? I can't seem to use the rule in relation to the the flow of current for the diagram. How would your curled fingers mimic the direction of flow in the motor?
Sydney Boys
don't use it on the actual DC motor coil (drawn in bold).
Solenoid rule on the electromagnets. Draw the poles. You get the magnetic field. This is B
This magnetic field then influences the current on the DC motor coil. This part is qv.
Then right hand rule F=qvB, t=rF for torque and hence the rotation direction.
Mega brain moment holy shit I think I got it.curl ur fingers in direction of current
follow along the coil for both lhs and rhs and thumb points to north pole
View attachment 31963
Mega brain moment holy shit I think I got it.This vid was kinda nice if you just want a little refresher. So basically you simplify everything so that it's just a positive flowing to the negative terminal. The motor part is basically just the solenoid, correct me if I'm incorrect.
Doesn’t conventional current always flow from positive to negative? Therefore the negative terminal should always be the North (like a solenoid where entry is pos and exit is neg terminal where thumb is at the exiting end)? My question now is what distinguishes C from D and why?View attachment 31964
these are what vishay was referring to as solenoids.
It's because the negative solenoid in C is actually in the opposite direction to the other solenoid so they don't create a continuous uniform/radial field i think. So the forces on each coil edge is canceled out.Doesn’t conventional current always flow from positive to negative? Therefore the negative terminal should always be the North (like a solenoid where entry is pos and exit is neg terminal where thumb is at the exiting end)? My question now is what distinguishes C from D and why?