A non conducting disc of radius a and uniform positive surface charge density σ is placed on the ground with its axis vertical. A particle of mass m and charge q is dropped, along the axis of the disc from a height H with zero initial velocity. It was observed that its velocity becomes zero just when it reaches the disc. The value of 3Ha is (Given qm=4ϵogσ)

A non conducting disc of radius a and uniform positive surface charge

1.	A non conducting disc of radius a and uniform positive surface charge density σ is placed on the ground with its axis vertical. A particle of mass m and charge q is dropped, along the axis of the disc from a height H with zero initial velocity. It was observed that its velocity becomes zero just when it reaches the disc. The value of 3Ha is (Given qm=4ϵogσ)
Answer» A non conducting disc of radius $a$ and uniform positive surface charge density $σ$ is placed on the ground with its axis vertical. A particle of mass $m$ and charge $q$ is dropped, along the axis of the disc from a height $H$ with zero initial velocity. It was observed that its velocity becomes zero just when it reaches the disc. The value of $\frac{3 H}{a}$ is (Given $\frac{q}{m} = \frac{4 ϵ_{o} g}{σ}$ )

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