Explain the fig of magnetisation and demagnetisation in NCERT page240?
This is the case of an inductor. In inductor there is a phase leg 90 degree between voltage and current.
Her four graphs are given with respect to time, one is for current , one is for voltage , one is for flux and one is for energy i.e. product of voltage and current.
Take the interval of 0-1 second.
At 0, current is zero, voltage is maximum, hence energy is zero.
Since we are using AC source so magnitude of current and voltage will change with time.
Between the 0-1, both voltage and current are non zero and positive so energy is also positive and positive energy means energy is extracted from the source, and flux also increases as current increases so this is the case of magnetisation.
Between 1-2
When current decreases, energy decreases i.e. given back to the source and flux through the coil decreases,this is the case of demagnetisation.
At 1, voltage is voltage is zero so energy , at this point complete demagnetisation occurs.
same thing happens in 2-3 and 3-4, but direction of current is in opposite direction, magnetisation occurs in opposite and demagnetisation occurs in opposite or reverse direction.
Her four graphs are given with respect to time, one is for current , one is for voltage , one is for flux and one is for energy i.e. product of voltage and current.
Take the interval of 0-1 second.
At 0, current is zero, voltage is maximum, hence energy is zero.
Since we are using AC source so magnitude of current and voltage will change with time.
Between the 0-1, both voltage and current are non zero and positive so energy is also positive and positive energy means energy is extracted from the source, and flux also increases as current increases so this is the case of magnetisation.
Between 1-2
When current decreases, energy decreases i.e. given back to the source and flux through the coil decreases,this is the case of demagnetisation.
At 1, voltage is voltage is zero so energy , at this point complete demagnetisation occurs.
same thing happens in 2-3 and 3-4, but direction of current is in opposite direction, magnetisation occurs in opposite and demagnetisation occurs in opposite or reverse direction.