A negatively charged ebonite rod attracts a suspended ball of straw. Can we infer that the ball is positively charged ?

A positively charged glass rod attracts a suspended object. Can we conclude that the object is negatively charged ?

A positively charged glass rod attracts a suspended pith-ball. Does it imply that te pith-ball is negatively charged?

A positively charged glass rod repels a suspended object. Can we conclude that the object is positively charged ?

The negatively charged dust particles are attracted by

A negatively charged ebonite rod is made to touch an insulated brass sphere. The brass sphere gets electrically charged by the process of Induction/ conduction

When a negatively charged ebonite rod is brought near a negatively charged and freely suspended ball, then the ball :