Multiple choice (show your work if any):
1) Two point charges q1=-10^-5 C and q2=-9×10^-5 C are placed respectively at two points A and B 40 cm apart. The electric field is null at a point C of [AB] such that :
a) AC=50cm b) AC=10cm c) AC=20cm d) point C doesn't exist
2) Same given. The electric field is null at a point C outside [AB] such that :
a) AC=50cm b) AC=30cm c) AC=20cm d) point C does not exist
2 answers
do your own work
answer:C does not exist
hey vicky solve it like this:
since electric field at C is equal to 0.therefore,
Eac=Ebc
since we know that electric field ,E=kq/r^2
let r be represented by x
where k=propotionality constant
#k*10^-5/x^2=k*9*10^-5/(40-x)^2
on solving u get a quadratic equation as
8x^2+80x-1600=0
this equation has no solution
hence C at distance x does not exist
hey vicky solve it like this:
since electric field at C is equal to 0.therefore,
Eac=Ebc
since we know that electric field ,E=kq/r^2
let r be represented by x
where k=propotionality constant
#k*10^-5/x^2=k*9*10^-5/(40-x)^2
on solving u get a quadratic equation as
8x^2+80x-1600=0
this equation has no solution
hence C at distance x does not exist
1 answer