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GRE Physics

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
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. Volumetric Expansion
Braking Radiation
B = µ0 I n
V = V0 + V0 a ?T
Always Real

2. Angular momentum - Central Force Motion
W_A < W_I
DS = 0 - dQ = 0 - P V^? = constant
L = mr²d?/dt
DW/dq

3. Partition Function
Q = CVexp(-t/RC)
F = -2*m(? x r)
E_n = -µ c^2 Z a^2 / (2n^2) - with µ = m_1 m_2 / (m_1 + m_2)
? exp(-e/t)

4. Quant: Expectation Value
L = µ N² A / l : N = number of turns - A = cross sectional area -l = length
U - ts = -tlog(Z)
?max = 2.898 x 10 -³ / T
<?|O|?>

5. Clausius-Clapeyron Equation
J = ? Fdt
C_eq = (? 1/C_i)^-1
F = I L X B
Dp/dt = L / (t ?V)

6. EM: AC Resonance
F = µ0 q v I / 2pr
X_L = X_C or X_total = 0
U - ts = -tlog(Z)
Cos[?] Sin[?] -Sin[?] Cos[?]

7. Complex impedance (expressions for capacitor and inductor)
Z_c = -i/(?C) ; Z_L = i ? L
Triplet: symmetric - net spin 1 Singlet: antisymmetric - net spin 0
1s² - 2s² 2p6 - 3s² 3p6 3d¹°
I = Im (sinc²(a)) ; a = pai sin(?) / ?

8. Malus Law

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9. Stefan-Boltzmann law for blackbodies (power per area and T)
P/A = s T^4
DW/dq
C_eq = (? 1/C_i)^-1
E²-p²c²

10. E field of a capacitor (d->0)
Exp(N(µ-e)/t)
E = s/e_0
F = -2*m(? x r)
P = µ_0 q^2 a^2/(6Pi c); No radiation along the axis of acceleration

11. Stoke'S Theorem
.5 CV²
(3/2) n R ?t
Int ( A . dr) = Int ( del x A) dSurface
S = k ln[O] ; dS = dQ/T

12. Mean electron drift speed
Z_C + Z_L = 0. Occurs when ?=1/Sqrt[L C]
J/(ne) n: atom density
Asin(?) = m?
µ0 I1I2 / (2pd)

13. Kepler'S Three Laws
?max = 2.898 x 10 -³ / T
W_A < W_I
D/dt (.5*r^2 d?/dt) = 0 - r(?) = a(1-e²)/(1+ecos(?)) - T²aA³
Series: 1/k_eq = 1/k_1 + 1/k_2; Parallel: k_eq = k_1 + k_2

14. Invariant spatial quantity
?mc²
Series: 1/k_eq = 1/k_1 + 1/k_2; Parallel: k_eq = k_1 + k_2
I = Im (sinc²(a)) ; a = pai sin(?) / ?
Ct²-x²-y²-z²

15. Source Free RL Circuit
Interference: (m+.5)? = d sin(?) Diffraction: m? = w sin(?)
µ0 I / 2pR
X_L = i?L
IR + Ldi/dt = 0 - I = I0e(-tL/R) Work = 1/2 L I0^2

16. Mech: Force of Friction
F_f = µ*F_N
T^2 = k R^3 - k=constant
IR + Ldi/dt = 0 - I = I0e(-tL/R) Work = 1/2 L I0^2
V = V0 + V0 a ?T

17. Atom: Hydrogen Wave Function Type
Interference: (m+.5)? = d sin(?) Diffraction: m? = w sin(?)
Exponentially decreasing radial function
0
Int ( A . dr) = Int ( del x A) dSurface

18. Error in the mean if each measurement has the same uncertainty s
?~T
(° of Freedom)kT/2
S_mean = s/Sqrt[N]
PdV +dU

19. Relativistic length contraction
L = L_0 Sqrt[1-v^2/c^2]
I = Im (sinc²(a)) ; a = pai sin(?) / ?
DW = P dV
?s = 0 - ?l = ±1

20. EM: SHO (Hooke)
qvb = mv²/R
div(E) = ?/e_0 - curl(E) = der(B)/der(t) - div(B) = 0 - curl(B) = µ_0J + µ_0e_0*der(E)/der(t)
ma + kx = 0
4H + 2e- ? He +2? + 6?

21. Wein'S Displacement Law
PdV +dU
DW = P dV
(° of Freedom)kT/2
?max = 2.898 x 10 -³ / T

22. Inductance of Solenoid
.5 LI²
L = µ N² A / l : N = number of turns - A = cross sectional area -l = length
1/vLC
B = µ0 I n

23. Thermo: 1st Law
A[B -C] + [A -C]B
F = s * T4
dQ = dW +dU
1/vLC

24. Mech: Virial Theorem
? (t-vx/c²)
<T> = -<V>/2
Measurements close to true value
X_L = X_C or X_total = 0

25. Relativistic Momentum
P/A = s T^4
ds² = (c*dt)² - ?(x_i)²
u dm/dt
?mv

26. Atom: Orbital Config
4H + 2e- ? He +2? + 6?
div(E) = ?/e_0 - curl(E) = der(B)/der(t) - div(B) = 0 - curl(B) = µ_0J + µ_0e_0*der(E)/der(t)
<?|O|?>
1s² - 2s² 2p6 - 3s² 3p6 3d¹°

27. First law of thermodynamics (explain direction of energy for each term)
Q = U + W Q = heat in system - U = total energy in system - W = work done by gas
u dm/dt
Measurements close to true value
Product ( nj ^ vj ) = Product(nqj ^ vj exp (-vj F(int)/Tau))

28. Lagrangian and Lagrange'S equation
?L/A - L = length - A = cross sectional area - rho is electrical resistivity
? = ?_0 Sqrt[(1+v/c)/(1-v/c)]
?s = 0 - ?l = ±1
L = T - V dL/dq = d/dt dL/dqdot

29. Solid: Resistivity of Semi-Conductor
F = R/2
1s² - 2s² 2p6 - 3s² 3p6 3d¹°
?~1/T
P² ~ R³

30. Virial Theorem
Z_C + Z_L = 0. Occurs when ?=1/Sqrt[L C]
ma + kx = 0
1. Heat is energy 2. Entropy never decreases 3. Entropy approaches a constant value as t -> 0...
<T> = 1/2 * <dV/dx>

31. Lensmaker Equation - Thin Lens
Q = U + W Q = heat in system - U = total energy in system - W = work done by gas
1/f = (n-1)(1/R1 - 1/R2) if both positive - they are convex - concave
µ = m_e/2
F = I L X B

32. Mech: Rotational Energy
F = -2*m(? x r)
H = H_0 + ?H
T = I?²/2
I = Im (sinc²(a)) ; a = pai sin(?) / ?

33. EM: Electromagnetic inertia
J = ? Fdt
L^2 |E - scl - m> = hbar^2 scl(scl+1) |E -scl -m> L_z |E - scl - m> = hbar m |E - scl - m>
Faraday/Lenz: current inducted opposes the changing field
C_eq = (? 1/C_i)^-1

34. Source-free RC Circuit
Triplet: symmetric - net spin 1 Singlet: antisymmetric - net spin 0
CdV/dt + V/R = 0 V(t) = V0 exp(-t/RC) I(t) = I(0) exp(-t/RC)
D/dt (.5*r^2 d?/dt) = 0 - r(?) = a(1-e²)/(1+ecos(?)) - T²aA³
I = V/R exp(-t/RC)

35. EM: Bremsstrahlung (translation)
I = I_cm + (1/2)m d^2
F = f* (c+v_r)/(c+v_s)
Braking Radiation
A[B -C] + [A -C]B

36. Quant: Commutator Relation [AB -C]
Let w_i = 1/s_i^2;x_wav = S(w_i x_i) / Sw_i - s_xwav = 1/Sw_i
V = V0 + V0 a ?T
?max = 2.898 x 10 -³ / T
A[B -C] + [A -C]B

37. Lab: Precision of Measurements
DB = ( µ_0 I/(4Pi) ) dl(cross)rhat/r^2
Measurements close to mean
Sin(?) = ?/d
U - ts = -tlog(Z)

38. Thermo: Adiabatic Work vs Isothermal Work
P1V1 - P2V2 / (? - 1)
W_A < W_I
J = E s - s = Conductivity - E = Electric field
Let w_i = 1/s_i^2;x_wav = S(w_i x_i) / Sw_i - s_xwav = 1/Sw_i

39. Magnetic Field For Current in Long Wire
F = µ0 q v I / 2pr
I ' = I cos²(?)
µ0 I / 2pR
Z = ?g_i*exp(-E/kT)

40. Energy for orbits: Hyperbole - Ellipse - Parabola - Circle
E = Vmin : circle - E = 0 : parabola - E<0 : el - E>0 : h
? (t-vx/c²)
1/vLC
(3/2) n R ?t

41. Quant: Orthogonality of States
? = 5/3
qvb = mv²/R
<?1|?2> = 0 ? Orthogonal
Braking Radiation

42. Time Lorentz Transformation
? (t-vx/c²)
E = <?| H |?>
4H + 2e- ? He +2? + 6?
µ = m_e/2

43. EM: Electric Field inside of Conductor
0
SR: ?=? - ß=? E = ?mc² = v(p²c² + m²c4)
P = µ_0 q^2 a^2/(6Pi c); No radiation along the axis of acceleration
F = mv²/r

44. Bar magnets -- direction of B field lines - earth'S B field
North to south; Earth has S magnetic pole at the N geographic pole and vice versa.
Q = CVexp(-t/RC)
?= h/v(2mE)
.5 CV²

45. Energy in terms of partition function
?scl = +/-1;?m = 0 - +/-1;?S_tot = 0;(?j = ?scl + ?S_tot)
U = t^2 d/dt (logZ)
P/A = s T^4
<T> = -<V>/2

46. Springs in series/parallel
Series: 1/k_eq = 1/k_1 + 1/k_2; Parallel: k_eq = k_1 + k_2
Sin(?) = ?/d
<T> = -<V>/2
T^2 = k R^3 - k=constant

47. Mech: Centripetal Force
(3/2) n R ?t
Ct²-x²-y²-z²
F = mv²/r
Exponential - E = -ma²/2hbar² - a is strength of delta wellt

48. Commutator identities ( [B -A C] - [A -B] )
V = -L di/dt
Const: 2t = (n +.5)? Destructive 2t = n?
A[B -C] = A[B -C]+[B -A]C [A -B] = -[B -A]
<T> = -<V>/2

49. Force/length between two wires
Product ( nj ^ vj ) = Product(nqj ^ vj exp (-vj F(int)/Tau))
µ0 I1I2 / (2pd)
Opposing charge induced upon conductor
F = R/2

50. Magnetic Field of a long solenoid
Z²/n² (m_red/m_elec)
?_max = b/T
B = µ0 I n
u dm/dt