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NEET-XII-Physics

pp year:2018

with Solutions -
Qstn# 12 Prvs-QstnNext-Qstn
  • #12
    A set of 'n' equal resistors, of value 'R' each,
    are connected in series to a battery of emf 'E'
    and internal resistance 'R'. The current drawn is I.
    Now, the 'n' resistors are connected in parallel
    to the same battery. Then the current drawn from
    battery becomes 10 I. The value of 'n' is :-
    (1) 10
    (2) 11
    (3) 20
    (4) 9
    digAnsr:   1
    Ans : (1)
    Sol. =
    +
    E
    I
    nR R
    ..... (1)
    = =
    +
    +
    E nE
    10I
    R R nRR
    n
    .....(2)
    From (1) & (2),
     
    =  
    +  + 
    E E
    n 10
    R nR nR R
    n = 10