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GRE Physics

Instructions:

Answer 50 questions in 15 minutes.
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Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Thermo: Average Total Energy
?~1/T
(° of Freedom)kT/2
T = I?²/2
Let w_i = 1/s_i^2;x_wav = S(w_i x_i) / Sw_i - s_xwav = 1/Sw_i

2. EM: Reactance of Capacitor
T^2 = k R^3 - k=constant
µ = m_e/2
Always Real
X_C = 1/(i?C)

3. EM: Lorentz Force
E = Vmin : circle - E = 0 : parabola - E<0 : el - E>0 : h
CdV/dt + V/R = 0 V(t) = V0 exp(-t/RC) I(t) = I(0) exp(-t/RC)
Exponential - E = -ma²/2hbar² - a is strength of delta wellt
F = qv×B

4. Pauli matrices
S = (hbar/2) s ;with S = S_x xhat + S_y yhat + S_z zhat -s = s_x xhat + s_y yhat + s_z zhat
.5 LI²
<?|O|?>
NC?T

5. Volumetric Expansion
DW = P dV
Series: 1/k_eq = 1/k_1 + 1/k_2; Parallel: k_eq = k_1 + k_2
ma + kx = 0
V = V0 + V0 a ?T

6. Magnetic field due to a segment of wire
North to south; Earth has S magnetic pole at the N geographic pole and vice versa.
B = µ0 I (sin(?1)-sin(?2))/(4pr) r = distance from point
? = ?0 root((1-v/c)/(1+v/c))
KE = 1/2 * µ (dr/dt)² L = µ r x v

7. Bar magnets -- direction of B field lines - earth'S B field
dQ = dW +dU
H = H_0 + ?H
North to south; Earth has S magnetic pole at the N geographic pole and vice versa.
1s² - 2s² 2p6 - 3s² 3p6 3d¹°

8. Gibbs Factor
Isentropic
F = qv×B
Exp(N(µ-e)/t)
F = s * T4

9. How to derive cylcotron frequency
1/f = (n-1)(1/R1 - 1/R2) if both positive - they are convex - concave
F = -2*m(? x r)
Z = ?g_i*exp(-E/kT)
qvb = mv²/R

10. Relativistic Momentum
P1V1 - P2V2 / (? - 1)
C_eq = ?C_i
µ0 I / 2pR
?mv

11. Focal point of mirrror with curvature
Measurements close to mean
I = I_cm + (1/2)m d^2
J = E s - s = Conductivity - E = Electric field
F = R/2

12. Invariant Energy Quantity
µ = Current * Area T = µ x B
E²-p²c²
? = h/mv
<?1|?2> = 0 ? Orthogonal

13. EM: Reactance of Inductor
S = k ln[O] ; dS = dQ/T
J = ? Fdt
X_L = i?L
dU = 0 ? dS = ?dW/T

14. EM: Electric Field inside of Conductor
L = L_0 Sqrt[1-v^2/c^2]
S = k ln[O] ; dS = dQ/T
0
Opposing charge induced upon conductor

15. Energy for orbits: Hyperbole - Ellipse - Parabola - Circle
<T> = 1/2 * <dV/dx>
Z_c = -i/(?C) ; Z_L = i ? L
E = Vmin : circle - E = 0 : parabola - E<0 : el - E>0 : h
Hbar*?³/(p²c³exp(hbar?/t)-1)

16. QM: de Broglie Wavelength
?= h/v(2mE)
C = 4pe0 ab/(a-b) = inner and outer radii
A[B -C] = A[B -C]+[B -A]C [A -B] = -[B -A]
F = mv²/r

17. Resistance - length - area - rho
ih_barL_z
µ=s^2
?L/A - L = length - A = cross sectional area - rho is electrical resistivity
PdV +dU

18. Bernoulli Equation
P +1/2 ? v² + ?gh = Constant
W_A < W_I
.5 CV²
I_z = I_x + I_y (think hoop symmetry)

19. EM: AC Resonance
X_L = X_C or X_total = 0
E = <?| H |?>
ds² = (c*dt)² - ?(x_i)²
N d flux / dt

20. Adiabatic means
1/ne - where n is charge carrier density
div(E) = ?/e_0 - curl(E) = der(B)/der(t) - div(B) = 0 - curl(B) = µ_0J + µ_0e_0*der(E)/der(t)
<T> = 1/2 * <dV/dx>
Isentropic

21. Clausius-Clapeyron Equation
DS = 0 - dQ = 0 - P V^? = constant
Dp/dt = L / (t ?V)
I = I_cm + md²
N d flux / dt

22. Charge in Capacitor
?L/A - L = length - A = cross sectional area - rho is electrical resistivity
?mv
Q = CVexp(-t/RC)
I = I_0 Cos[?]^2

23. Lensmaker Equation - Thin Lens
Z²/n² (m_red/m_elec)
1/f = (n-1)(1/R1 - 1/R2) if both positive - they are convex - concave
DW = P dV
v(mean)

24. Resonance frequency of LC circuit
v(mean)
X_L = X_C or X_total = 0
? exp(-e/t)
1/vLC

25. Boltzmann / Canonical distribution
P(s) = (1/Z) Exp[-E(s)/(k T)] Z = S_s(Exp[-E(s)/(k T)])
DB = ( µ_0 I/(4Pi) ) dl(cross)rhat/r^2
? = ?_0 Sqrt[(1+v/c)/(1-v/c)]
E = Z²*E1

26. De Broglie wavelength
L = µ N² A / l : N = number of turns - A = cross sectional area -l = length
P = µ_0 q^2 a^2/(6Pi c); No radiation along the axis of acceleration
? = h/p
1/f = (n-1)(1/R1 - 1/R2) if both positive - they are convex - concave

27. Rocket Equation
? = ?0 root((1-v/c)/(1+v/c))
P +1/2 ? v² + ?gh = Constant
Const: 2t = (n +.5)? Destructive 2t = n?
Dv = -udm/m - v = v0 + u ln(m0/m)

28. Thermo: Isothermal
Series: 1/k_eq = 1/k_1 + 1/k_2; Parallel: k_eq = k_1 + k_2
J = ? Fdt
S = k ln[O] ; dS = dQ/T
dU = 0 ? dS = ?dW/T

29. Work done on a gas
Faraday/Lenz: current inducted opposes the changing field
Product ( nj ^ vj ) = Product(nqj ^ vj exp (-vj F(int)/Tau))
DW = P dV
I = -(c ?t)^2 + d^2

30. Triplet/singlet states: symmetry and net spin
Triplet: symmetric - net spin 1 Singlet: antisymmetric - net spin 0
I = I_cm + md²
P +1/2 ? v² + ?gh = Constant
Always Real

31. Source Free RL Circuit
1. Heat is energy 2. Entropy never decreases 3. Entropy approaches a constant value as t -> 0...
IR + Ldi/dt = 0 - I = I0e(-tL/R) Work = 1/2 L I0^2
Let w_i = 1/s_i^2;x_wav = S(w_i x_i) / Sw_i - s_xwav = 1/Sw_i
ma + kx = 0

32. E field of a capacitor (d->0)
Product ( nj ^ vj ) = Product(nqj ^ vj exp (-vj F(int)/Tau))
Z²/n² (m_red/m_elec)
E = s/e_0
A[B -C] = A[B -C]+[B -A]C [A -B] = -[B -A]

33. EM: Method of Images
Z = ?g_i*exp(-E/kT)
Opposing charge induced upon conductor
E = Vmin : circle - E = 0 : parabola - E<0 : el - E>0 : h
S_mean = s/Sqrt[N]

34. Rayleigh'S Criterion
C = 4pe0 ab/(a-b) = inner and outer radii
?L/A - L = length - A = cross sectional area - rho is electrical resistivity
Sin(?) = ?/d
4H + 2e- ? He +2? + 6?

35. Thermo: Blackbody Radiation
F = s * T4
A[B -C] + [A -C]B
µ = m_e/2
P1V1 - P2V2 / (? - 1)

36. Atom: Bohr Theory Ionization
E = Z²*E1
ih_barL_z
W_A < W_I
?L/A - L = length - A = cross sectional area - rho is electrical resistivity

37. Effective Potential
F_f = µ*F_N
Let w_i = 1/s_i^2;x_wav = S(w_i x_i) / Sw_i - s_xwav = 1/Sw_i
V(r) + L²2/2mr²
?max = 2.898 x 10 -³ / T

38. Doppler Shift in Frequency
F = f* (c+v_r)/(c+v_s)
I ' = I cos²(?)
<?|O|?>
H = H_0 + ?H

39. Mech: Centripetal Force
? = ?_0 Sqrt[(1+v/c)/(1-v/c)]
L = L_0 Sqrt[1-v^2/c^2]
F = mv²/r
? = 1.22?/D

40. Solid: Resistivity of Semi-Conductor
SR: ?=? - ß=? E = ?mc² = v(p²c² + m²c4)
?~1/T
Braking Radiation
I = V/R exp(-t/RC)

41. Law of Mass Action
<?|O|?>
When you apply a uniform electric field - it induces a dipole moment and interacts with it - and that effect depends on |mj |. So if j is an integer - splits (asymmetrically) into j+1 levels - and if j is a half integer - splits (asymmetrically) into
Product ( nj ^ vj ) = Product(nqj ^ vj exp (-vj F(int)/Tau))
V = V0 + V0 a ?T

42. Stark Effect
F = mv²/r
When you apply a uniform electric field - it induces a dipole moment and interacts with it - and that effect depends on |mj |. So if j is an integer - splits (asymmetrically) into j+1 levels - and if j is a half integer - splits (asymmetrically) into
DS = 0 - dQ = 0 - P V^? = constant
W_A < W_I

43. Thin Film Theory: Constructive / Destructive Interference
J = E s - s = Conductivity - E = Electric field
H = H_0 + ?H
Const: 2t = (n +.5)? Destructive 2t = n?
?? = h/mc * (1-cos(?))

44. Atom: Hydrogen Wave Function Type
PdV +dU
Cos[?] Sin[?] -Sin[?] Cos[?]
Exponentially decreasing radial function
Braking Radiation

45. Coriolis Force
W_A < W_I
1. Heat is energy 2. Entropy never decreases 3. Entropy approaches a constant value as t -> 0...
F = -2*m(? x r)
1s² - 2s² 2p6 - 3s² 3p6 3d¹°

46. Astro: p-p Chain
1s² - 2s² 2p6 - 3s² 3p6 3d¹°
4H + 2e- ? He +2? + 6?
Measurements close to true value
Isentropic

47. Relativistic interval (which must remain constant for two events)
I = -(c ?t)^2 + d^2
Z_c = -i/(?C) ; Z_L = i ? L
(° of Freedom)kT/2
Q = U + W Q = heat in system - U = total energy in system - W = work done by gas

48. RLC resonance condition
Z_C + Z_L = 0. Occurs when ?=1/Sqrt[L C]
E = <?| H |?>
In Zeeman effect - the contribution of electron spin to total angular momentum means that it isn'T always three lines and they are not always equally spaced.
U - ts = -tlog(Z)

49. Induced EMF of solenoid
? exp(-e/t)
N d flux / dt
? = 1.22? / d
Interference: (m+.5)? = d sin(?) Diffraction: m? = w sin(?)

50. Stefan-Boltzmann law for blackbodies (power per area and T)
? = ?_0 Sqrt[(1+v/c)/(1-v/c)]
Opposing charge induced upon conductor
P/A = s T^4
I = -(c ?t)^2 + d^2