A pitch ball covered with a tin foil having a
mass m kg hangs by a fine silk thread of
length r metres in an electric field E. When
the ball is given an electric charge of q
coulomb, it stands out d metre apart from
the vertical line. The magnitude of an electric
field will be
A pitch ball covered with a tin foil having a
mass m kg hangs by a fine silk thread of
length r metres in an electric field E. When
the ball is given an electric charge of q
coulomb, it stands out d metre apart from
the vertical line. The magnitude of an electric
field will be
mass m kg hangs by a fine silk thread of
length r metres in an electric field E. When
the ball is given an electric charge of q
coulomb, it stands out d metre apart from
the vertical line. The magnitude of an electric
field will be