# HSC Physics MC Thread (1 Viewer)

#### spatula232

##### Active Member
Believe the answer is B. Check your right hand palm rule again. Your thumb should be pointing upwards, with your fingers curling around in the anti-clockwise direction; making a south pole at the bottom of the solenoid

#### Mr_Kap

##### Well-Known Member
You might have the right hand rule the wrong way. I think the fingers point in the north direction of the b-field so the field goes up
mag field direction goes from NORTH to SOUTH though, so that's why you point your thumb to the south

#### Mr_Kap

##### Well-Known Member
Believe the answer is B. Check your right hand palm rule again. Your thumb should be pointing upwards, with your fingers curling around in the anti-clockwise direction; making a south pole at the bottom of the solenoid
why should thumb point upwards???

mag field direction goes from NORTH to SOUTH

#### atargainz

##### Active Member
Believe the answer is B. Check your right hand palm rule again. Your thumb should be pointing upwards, with your fingers curling around in the anti-clockwise direction; making a south pole at the bottom of the solenoid
this question put me on tilt wtf, correct me if i'm wrong if you make a south pole at the bottom of the solenoid, wouldn't the mag field go down? (because goes from north to south)

#### Mr_Kap

##### Well-Known Member
OR IS IT THE OPPOSITE DIRCTION IN THE RIGHT HAND CURL RULE!!!!

WOW!! NEVER KNEW THAT!!

cant believe its opposite --> Mind blown

#### Mr_Kap

##### Well-Known Member
CHECK THIS PICTURE OUT:

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#### atargainz

##### Active Member
why should thumb point upwards???

mag field direction goes from NORTH to SOUTH
For the RHGR, thumb points to the north pole, not in the direction of the mag field I believe

#### malcolm21

##### Active Member
CHECK THIS PICTURE OUT:

bruh

#### Mr_Kap

##### Well-Known Member

was an accident i swear.. lol.

I got the picture workin now.

#### Mr_Kap

##### Well-Known Member
I swear you learn something knew everyday.

So does the mag field ALWAYS go to the north if using the CURL rule??

#### keepLooking

##### Active Member
OR IS IT THE OPPOSITE DIRCTION IN THE RIGHT HAND CURL RULE!!!!

WOW!! NEVER KNEW THAT!!

cant believe its opposite --> Mind blown
Same here. I feel stupid forgetting Year 11 stuff. ;(

#### atargainz

##### Active Member
da fuk I still don't get why it's B

#### DattMyball

##### New Member
I swear you learn something knew everyday.

So does the mag field ALWAYS go to the north if using the CURL rule??
Yeah pretty sure it does

#### keepLooking

##### Active Member
da fuk I still don't get why it's B
Lenz's Law. As magnet with South pole is moving upwards, the solenoid will tend to create a magnetic field with the South pole downwards to PREVENT the magnet from cumming into him. Right Hand Grip rule, you point your thumb to the ceiling (up) and your fingers will wrap around anti-clockwise (when viewed from bird's eye view).

vv
Then you move your eyes away from your right hand and shoot it to the roof.

#### Mr_Kap

##### Well-Known Member
da fuk I still don't get why it's B
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 faces to THE NORTH!!!! SO FACES UP!!!

#### DattMyball

##### New Member
da fuk I still don't get why it's B
You can also use the curl rule on one of the wires (where thumb is current and fingers are field). If you look at the front wires, to make the field inside the coil where the magnet is be south at the bottom you point thumb right. You see the bit of fingers that would be in the middle of the coil going up north

#### keepLooking

##### Active Member

Anyone care to explain why it is B?

What I thought was:

$\bg_white \\a = \frac{F}{m}\\Where F is constant for both but mass is different.$

$\bg_white \\m_{a} = 6.64 \times 10^{-27} and m{p} = 1.673 \times 10^{-27}\\ \frac{1}{m_{a}} \div \frac{1}{m_{p}} = 0.25$

#### atargainz

##### Active Member
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 faces to THE NORTH!!!! SO FACES UP!!!

Even if your thumb faces upwards, isn't it asking for the direction of the magnetic field which is always north --> south?

#### Khan.Paki

##### 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?

#### rowcache

##### New 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=2/4=.5

@keepLooking

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