Units and Formulas by ICSEHUB
(based on ICSE class10 Syllabus)
FORCE 

Concept 
Formula 
S.I. 
CGS 
Force 
m x a 
Newton (N) 
dyne (10^{5}
N) 
Torque 
F
x ( ⊥ distance between Point of action and axis) 
Newtonmeter 
dynecm 
Work , Energy and Power 

Concept 
Formula 
S.I. 
CGS 
Work 
Force x
Displacement x cosθ M x g x h Change in Kinetic
Energy 
Joule (J) 
erg (10^{7 }J) 
Power 
Work
/ Time 
Watt
(W) 
erg
/ sec 
Commercial Energy 
Power X Time 
Watthour &
KiloWatthour 

Energy 
Kinetic : ½ mv^{2} Potential
: mgh 
Joule
(J) 
erg
(10^{7 }J) 
Electron Volt 
Charge of 1
electron x 1V 
1.6 x 10^{19}J 
Not required 
Machines 

Concept 
Formula 
Mechanical Advantage (M.A) 
Load/Effort Effort Arm / Load
Arm 
Velocity Ratio (V.R.) 
Effort
Velocity / Load Velocity Effort
Distance / Load Distance 
Efficiency 
(Work Output /
Work Input) M.A / V.R 
1 Horsepower = 746 Watt
Mechanical Energy = K.E. + P.E.
MA and VR have no units as they are
ratios.
Light and Sound 

Concept 
Formula 
Frequency 
1/ Time Period (Hertz) 
Speed of light in a medium 
Wavelengh
x Frequency Wavelength
/ Time period 
Refractive Index 
sin i / sin r Speed of light in
vaccume / Speed of
light in other medium Real depth / Apparent depth 1 / sin c ; c = (critical angle) 
Lens Formula 
^{1}/_{f}
= ^{1}/v ^{1}/u v = image
distance u = object distance Very Important  v
 image Oh U(you)
 Object u 
Magnification 
Height of Image / Height of Object Image
distance / Object distance 
Power 
1
/ focal length of
lens in meters SI unit : Dioptre (D) Covenx +D , Concave D 
Magnifing Power 
1 + 0.25 / focal
length Unit
: Dioptre 
Speed of Sound 
2
x Distance / Time Taken 
Electricity 

Concept 
Formula 
Unit 
Current 
Charge /
Time (Q/t) 
Ampere 
Potentital Difference 
V
= Current x Resistance V
= IR V
= Emf  v 
Volt 
Resistance (R) 
Potential
Difference / Current Resistivity x
Length / Crosssection Area 
Ohm 
Emf 
Current
x Total Resistance Terminal
Voltage + Voltage Drop 
Volt 
Internal Resistance (r) 
# r = ( Emf/V  1)R 
Ohm 
Total Resistance 
R
+ r 
Ohm 
Resistivity 
R x a/L 
Ohmmeter 
Voltage Drop (v) 
Current
x Internal Resistance 
Volt 
Conductance 
1 / Resistance 
Mho 
Conductivity 
1
/ Resistivity 
1
/ ohm x meter 
Connection Resistance 
Series
: R = r_{1 }+ r_{2 } +
r_{3 }
. Parallel
:1/R = 1/r_{1 }+ 1/r_{2 } + 1/r_{3} 
Ohm 
Household Circuits 

Concept 
Formula 
Unit 
Electric Work (W) 
VIt I^{2}Rt 
Joule 
Power (P) 
V
x I W/t 
Watt 
Heat (H) 
I^{2}Rt 
Joule 
Electromagnetism 

Concept 
Formula 
Unit 
Force 
iBL 
Newton 
Magnetic Strength (B) 
F
/ IL 
Tesla 
Heat (H) 
I^{2}Rt 
Calorie or Joule 
EXAMINERS SUGESTIONS (Issued by Council)
a)
Avoid
selective study.
b)
Read
the questions heedfully and write answer in brief and to the point.
c)
Express
the answer only in SI units unless otherwise asked.
d)
Learn
the principles, laws and definitions accurately.
e)
Focus
more on conceptual learning rather than the rote learning.
f)
Make
observations and try to relate your learning with it.
g)
State
the meaning of the symbols if the answer is given in terms of any
formula/mathematical equation.
h)
Use
abbreviations/symbols which are standard/acceptable.
i)
Solve
at least the last five years I.C.S.E. question papers.
j)
Write
in a neat and legible handwriting.
k)
Avoid
changing the order of sequence of questions and numbering system while
attempting the paper.
l)
Express
final answer with proper unit as per the requirement of the question.
m) While writing the answers it is not only
important to cover all the points but also to present them in a proper
sequence.
n)
It is
better to inculcate the habit of underlining the important points or key words
in the answer.