Question

JEE MAINS PHYSICS QUESTION SEPTEMBER 2020

Answer 1

Answer:

option a is ur answer ........

Answer 2

we have to find the charge on capacitor 5μF

solution : see diagram, here it is clear that potential at A is zero.

let potential at C = x

charge on 2μF = q₁

charge on 4μF = q₂

charge on 5μF = q₃

total charge within region (as shown in diagram) = 0

⇒-q₁ + q₂ + q₃ = 0

we know, charge = potential × capacitor

so, q₁ = 2(6 - x)

q₂ = 4(x - 6)

and q₃ = 5(x - 0)

now, -2(6 - x) + 4(x - 6) + 5x = 0

⇒-12 + 2x + 4x - 24 + 5x = 0

⇒11x - 36 = 0

⇒x = 36/11

so, charge on 5μF = 5x = 5 × 36/11 = (180/11)μC

Therefore the correct option is (3)