Ø
During the charging of a
lead-acid cell its voltage increases.
Ø
Electric flux emanating
from an electric charge of + Q coulomb is Q.
Ø
Electromagnetic effect
is utilized for wattmeters and watthour meters.
Ø
Electrostatic effect is
utilized only for voltmeters only.
Ø
End-cell control system
is an economical system developed and used in place of using rheostat in
batteries for controlling the voltage.
Ø
For a given line
voltage, four heating coils will produce maximum heat when all the four coils
connected in parallel.
Ø
For any medium, electric
flux density D is related to electric
intensity E by the equation D = ε 0 ε r E
Ø
If a 220 V heater is
used on 110 V supply, heat produced by it will be one-fourth as much.
Ø
If D is the electric flux
density, then value of electric intensity in air
is D = εo
Ø
If dielectric slab of
thickness 5 mm and εr = 6 is inserted between
the plates of an air capacitor with plate separation of 8 mm, its capacitance
is almost doubled.
Ø
If relative permittivity
of mica is 5, its absolute permittivity is 5 εo.
Ø
In practice, earth is
chosen as a place of zero electric potential because it has almost constant
potential.
Ø
Induction type
instruments are used for AC measurements only. It can be used either as
ammeter, voltmeter and wattmeter.
Ø
Inside a charged
conducting sphere, the potential and electric intensity is Zero.
Ø
Inside a conducting
sphere, potential remains constant.
Ø
Kirchhoff’s current law
is applicable to junctions in a network.
Ø
Kirchhoff’s voltage law
is concerned with IR drops and battery e.m.f.
Ø
Magnetic effect, Thermal
effect, Electrodynamic effect and Electromagnetic effect is utilized for
ammeters and voltmeters.
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