Hong Kong Diploma of Secondary Education Examination
Physics
The following list of data, formulae and relationships will be provided in the question papers for
candidates’ reference:
List of data, formulae and relationships
Data
molar gas constant
Avogadro constant
acceleration due to gravity
universal gravitational constant
speed of light in vacuum
charge of electron
electron rest mass
permittivity of free space
permeability of free space
atomic mass unit
astronomical unit
light year
parsec
Stefan constant
Planck constant
R = 8.31 J mol−1 K−1
NA = 6.02 × 1023 mol−1
g = 9.81 m s−2 (close to the Earth)
G = 6.67 × 10−11 N m2 kg−2
c = 3.00 × 108 m s−1
qe = 1.60 × 10−19 C
me = 9.11 × 10−31 kg
0 = 8.85 × 10−12 C2 N−1 m−2
0 = 4 × 10−7 H m−1
u = 1.661  10−27 kg
(1 u is equivalent to 931 MeV)
AU = 1.50  1011 m
ly = 9.46  1015 m
pc = 3.09  1016 m = 3.26 ly = 206265 AU
 = 5.67  10−8 W m−2 K−4
h = 6.63 × 10−34 J s
Rectilinear motion
Mathematics
For uniformly accelerated motion :
Equation of a straight line
y = mx + c
Arc length
=rθ
Surface area of cylinder
= 2rh + 2r2
Volume of cylinder
= r2h
Surface area of sphere
= 4r2
4 3
r
=
3
v = u + at
1
s = ut + at 2
2
v2 = u2 + 2as
Volume of sphere
For small angles, sin  ≈ tan  ≈  (in radians)
Astronomy and Space Science
GMm
U =−
r
P = T 4
f
v

 
f0
c
0
Atomic World
1
2
me vmax = hf − 
2
gravitational potential energy
Stefan’s law
Doppler effect
Einstein’s photoelectric equation
4
1 
13.6
m q 

En = − 2  e2 e2  = − 2 eV

n 
8
h

n
0

energy level equation for hydrogen atom
=

h
h
=
p mv
1.22
d
de Broglie formula
Rayleigh criterion (resolving power)
Energy and Use of Energy

E=
illuminance
A
A(TH − TC )
Q
rate of energy transfer by conduction
=
t
d

U =
thermal transmittance U-value
d
1
P = ρAv 3
maximum power by wind turbine
2
Medical Physics
1.22
Rayleigh criterion (resolving power)

d
1
power =
power of a lens
f
I
L = 10 log
intensity level (dB)
I0
Z = c
acoustic impedance
I r ( Z 2 − Z1 ) 2
=
=
intensity reflection coefficient
I 0 ( Z 2 + Z1 ) 2
I = I 0 e − μx
transmitted intensity through a medium
Q1Q2
A1. E = mc ∆T
energy transfer during heating
and cooling
D1.
F=
A2. E = l ∆m
energy transfer during change
of state
D2.
E=
equation of state for an ideal gas
D3.
E=
kinetic theory equation
D4.
molecular kinetic energy
D5. R = R1 + R2
A3.
pV = nRT
1
Nmc 2
3
3 RT
A5. EK =
2N A
A4.
pV =
4π 0 r 2
Q
4π 0 r 2
V
d
l
R=
A
Coulomb’s law
electric field strength due to
a point charge
electric field between parallel plates
(numerically)
resistance and resistivity
resistors in series
D6.
1
1
1
=
+
R R1 R 2
resistors in parallel
v p
=
force
t t
D7.
P = IV = I 2 R
power in a circuit
B2. moment = F  d moment of a force
D8.
F = BQv sin 
force on a moving charge in a
magnetic field
B3. EP = mgh
gravitational potential energy
D9.
F = BIl sin 
force on a current-carrying
conductor in a magnetic field
kinetic energy
D10. B =
B1. F = m
1 2
mv
2
B4. EK =
B5. P = Fv
mechanical power
v2
=  2r
r
Gm1 m2
B6.
a=
B7.
F=
C1.
y =
C2.
d sin  = n
r
2
D
a
centripetal acceleration
Newton’s law of gravitation
2 πr
 0 NI
D11. B =
l
Φ
D12.  = N
t
V
N
D13. s  s
Vp N p
fringe separation in
double-slit interference
E1.
N = N0e−kt
diffraction grating equation
E2.
t1 =
2
C3.
1
u
+
1
v
=
1
f
0 I
equation for a single lens
ln 2
k
magnetic field due to a long
straight wire
magnetic field inside a long
solenoid
induced e.m.f.
ratio of secondary voltage to
primary voltage in a transformer
law of radioactive decay
half-life and decay constant
E3.
A = kN
activity and the number of
undecayed nuclei
E4.
E = mc 2
mass-energy relationship