# HSC Physics MC Thread (1 Viewer)

#### DattMyball

##### New Member
Wait I don't get it. If you put your thumb pointing upwards, don't your fingers still curl clockwise? So then how is it anti-clockwise?

#### keepLooking

##### Active Member
The alpha particle has twice the positive charge of the proton, and thus twice the force acting upon it. However, it has four times the mass so it is a=4/2=.5

@keepLooking
Wow fuck. I am a literal shithead. Thank you @rowcache.

#### rowcache

##### New Member
Wow fuck. I am a literal shithead. Thank you @rowcache.
No worries, Good luck tomorrow!

#### Khan.Paki

##### Member

In this question, shouldn't the current made in the coil generate a magnetic field such to oppose the magnet, hence the magnetic field in the coil will be down (as the bottom of the coil needs to be south to oppose the south end of the magnet).

This means when i use the right hand curl rule, the current is CLOCKWISE. So the answer should be D.

HOWEVER the answer is actually B. Why??? What am i doing wrong??
Can someone please explain why the magnetic field direction is going up? As Kap said, it should aim to oppose the initial change. Or is it because the magnetic field lines leave from north to south, and as north is on top, magnetic fields leave that direction?

#### sy37

##### Active Member
Can someone please explain why the magnetic field direction is going up? As Kap said, it should aim to oppose the initial change. Or is it because the magnetic field lines leave from north to south, and as north is on top, magnetic fields leave that direction?
^

can someone also go over the right hand grip rule or curl rule or whatever it is called for determining current direction ( I get the LHPR but I don't get the other one )

*EDIT*

The magnetic field direction is up as you said because the magnetic field lines leave from north to south I get it now, north is on top so magnetic field leaves that direction yeah

I don't get the current direction

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#### Mr_Kap

##### Well-Known Member
Can someone please explain why the magnetic field direction is going up? As Kap said, it should aim to oppose the initial change. Or is it because the magnetic field lines leave from north to south, and as north is on top, magnetic fields leave that direction?
CHECK THIS PICTURE OUT:
the current made in the coil generate a magnetic field such to oppose the magnet (lenz law), hence the magnetic field in the coil will be down (as the bottom of the coil needs to be south to oppose the south end of the magnet).

Due to the right hand CURL rule, the thumb ALWAYS faces to THE NORTH!!!! SO FACES UP!!! THIS IS WHAT HAPPENS WHEN YOU USE THE CURL RULE.

.

#### sy37

##### Active Member

Can someone explain to me how is the answer clockwise?

Right hand grip rule: thumb points in the direction of NORTH pole, fingers thus curl in the direction of current. Hence, anti-clockwise.

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#### Khan.Paki

##### Member
OKay I think its because since current in flowing from X to Y right, so ur thumb points downwards, hence your fingers curl clockwise.

#### atargainz

##### Active Member

Can someone explain to me how is the answer clockwise?

Right hand grip rule: thumb points in the direction of NORTH pole, fingers thus curl in the direction of current. Hence, anti-clockwise.
If you point your thumb down fingers will curl clockwise not anti

#### sy37

##### Active Member
oh nvm I got it..I was pointing my thumb towards the north magnetic pole not direction of the north pole lines themselves ty

#### DattMyball

##### New Member
yeah but the thumb must point north to the direction of the magnetic field as per the rule or am I missing something??
Use the right hand palm rule: thumb is current in wire, fingers out straight are the field lines, palm shows the direction the Fm will push the wire