I =
5
A
r =
5
cm
B = 20.0 μT
Right-Hand Rule
Case A · I points UP ↑
I
👍
B counter-clockwise
(viewed from above)
Case B · I points DOWN ↓
👎
I
B clockwise
(viewed from above)
Solenoid · fingers curl WITH current loops
B
👍
Fingers follow I around the coil
(thumb axial = B inside)
Right-Hand Rule · F = q v × B
Positive charge (+q)
🖐️
v
B
F
Flat right hand:
thumb=v · fingers=B
palm pushes out → F
Negative charge (−q)
🖐️
v
B
F
Same right hand · F reverses
(opposite direction for −q)
Fleming's Left-Hand Rule
Forefinger
B
Thumb
F
Central
v
(toward you)
Forefinger up (B) matches the scene above
q =
+e
|v| =
1.0
×10⁵ m/s
B =
10
mT
θ(v,B) =
90
°
F = 0.16 fN
no work
|v|
KE=½mv²
W
∫F·v dt
electric
|v|
KE=½mv²
W
∫F·v dt
magnetic
|v|
KE=½mv²
W
∫F·v dt
ELECTRIC — F not ⊥ v
MAGNETIC — F always ⊥ v
|v| =
1.0
×10⁵ m/s
B =
10
mT
|v| fixed · W = 0 · bigger B ⇒ tighter turn
m =
1.0
(mass)
v =
1.0
(speed)
q =
1.0
(charge)
B =
1.0
(field)
r
▮▮▮
qvB = mv²/r
r = mv/qB
θ =
45
° (angle)
v =
1.0
(speed)
B =
1.0
(field)
r
▮▮▮
p
▮▮▮
lap
lap
= same T
m =
1.0
(mass)
v =
1.0
(speed)
q =
1.0
(charge)
B =
1.0
(field)
T
N =
1
turns
I =
0.50
A
B =
0.10
T
θ(μ,B) =
45
°
τ = 0.0 μN·m
p =
5.0
×10⁻³⁰ C·m
E =
5.0
kV/m
θ(p,E) =
45
°
τ = 0.0 · U = 0.0
m =
5.0
A·m²
B =
5.0
×10⁻⁴ T
θ(m,B) =
45
°
τ = 0.0 · U = 0.0 · T = 0.0 s
I =
2
A
L =
0.5
m
B =
0.5
T
θ(L,B) =
90
°
Flip current →
F = 0.50 N
V =
12
V
d =
10
mm
E = V / d = 1200 V/m
E = V / d = 1200 V/m