When a negatively charged rod was passed over the sphere of an uncharged electrometer, the electrometer needle deviated.

When a negatively charged rod was passed over the sphere of an uncharged electrometer, the electrometer needle deviated.
a) Has the electrometer acquired an electric charge?
b) What sign of charge is formed on the sphere, rod and arrow of the electrometer?
c) What happens when the stick is removed from the electrometer?

a) Yes, the electrometer has acquired a negative charge.
b) A negative charge has formed on the sphere, rod and arrow.
c) The electrometer will remain charged.

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