If r1 is in series with parallel connected to r2 and r3, what happens to total current if r2 opens?

1 Answer
Jun 16, 2015

If r1 is in series with parallel connected to r2 and r3, the total current decreases if r2 opens.

Explanation:

Before opening of #r_2#

#R_(eq1)=r_1+(r_2r_3)/(r_2+r_3)#

#R_(eq1)=r_1+(r_3)/(1+r_3/r_2)##" "color(green)((1))#

After opening of #r_2#:

hence #r_2=#infinity#" "color(green)((2))#

write down#" "color(green)((1))# after substitution of#" "color(green)((2))#

#R_(eq2)=r_1+r_3#[since#r_3/r_2=0# if #r_2#=infinity]

#R_(eq2)=r_1+r_3##" "color(green)((3))#

from #" "color(green)((1))#&#color(green)((3))#

#R_(eq2)>R_(eq1)#

If resistance value is increased under constant application voltage and constant temperature ,then the rate of change of charge with respect to time decreases according to ohm's law.
#Iprop1/R# at constant voltage.

Therefore,the total current #color(blue)(decreases)# if r2 opens.