Question

List the Key Points to Remember from Chapter : Electricity [Class 10]

Include every main point to learn & make it clear.

Points : 50☺

Answer 1

Physical phenomena associated with the presence and flow of electric charge is known as electricity. Electricity and electrical phenomenon have a lot of applications in our day to day life and they also gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current.
Electricity occurs due to several types :
Electric charge: a property of some subatomic particles, which determines their electromagnetic interactions.
Electric current: a movement or flow of electrically charged particles, typically measured in amperes.
Electric field: an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity. Moving charges additionally produce a magnetic field.
Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
In this chapter we will study about electricity.

Answer 2

Electricity :- deals with the study of current in which branch known as Electricity .

Remembering points :-

# charge :- when any body loss or accept electrons then we can say that body have charge .

# SI unit of charge is Columns (C)

# we add charge by algebra rule .
e.g let -Q , 2Q are some charge
then total charge = -Q + 2Q =Q

# current :- change in charge per unit time is known as current .
it is denoted by I
I = dQ/dt

# current have both magnitude and direction but adding by parellogram rule so, current is scaler quantity .

# SI unit of current is Ampere (A)

(Note :- this is higher level , but point of exam veiw . you should remember )

# Columns law :- this concept just like Newton law of gravitation. which will you read in class 9 .

F = KQq/r²
where K is kappa constant
K = 9 x 10^9 Nm²/C²
Q and q are two charges ,
r is the distance between charges .

potential :- work done by a unit charge bringing from infinity to certain point is known as potential of that charge .
it is denoted by V .
V = KQ/r

# SI unit of potential is Volt (V)

#resistance :- this is a constant , which depend upon material where we passing current . its oppose the motion of current . it is denoted by R .

# SI unit of R is Ohm

# Ohm's law :- Ohm's law is the relation between potential difference, current and resistance .
e.g V = IR

# series combination of resistance :-
in series combination current through each wire are same .
Req = R1 + R2 +R3 +R4 +.........

Req is the resistance equivalent .
and R1 , R2 , R3 , ...... are resistance of given wire which are connected in series combination.

# Parallel combination of resistance :-
in this combination potential difference through each are same .

in parallel combination equivalent resistance find out by below equation .
1/Req = 1/R1 + 1/R2 + 1/R3 +.......

# energy ( Heat) formula, in electricity
E = H = I²Rt
=V²t/R
= VIt

# power formula ,
we know, power = energy /time
P = I²R
=V²/R
=VI

# principal of bulb :-

resistance of bulb =V²/P or R is inversely proportional to power .

(à) in Parallel combination of bulb
Pnet = P1 + P2 + P3 +......

(b) in series combination of bulb ,
1/Pnet = 1/P1 + 1/P2 + 1/P3 +.......

★ in parallel a bulb having more rated power glows more brightly . in series a bulb having less rated power glows more brightly .

# condition of balance wheat stone bridge.
P/Q = R/S
where{ P, Q} and { R, S} are opposite side resistance,

# R =dL/A

where R is resistance , d is specific resistance , L is length of wire , and A is CSA

# Resistance is depend upon temperature .
e.g R = R° ( 1 + adT)

where a is the constant ,
R is final resistance , R° is initial resistance dT is temperature change .

# Galvanometer :- A device which is used to detect a current .

# A Galvanometer is converted into an Ammeter by connecting a low resistance ( called shunt) in parallel with galvanometer .

★resistance of an ideal Ameter is zero

# A Galvanometer is converted into a voltmeter by connecting a high resistance in series with galvanometer .

★ resistance of an ideal Voltmeter is ∞