An electroscope is used to detect and measure charges what happens in electroscope when its disc is touched with a charged object

in an electroscope there is a metallic rod at the top there is a metallic disc or cup and at the end it has thin two metallic sheets when we rub a glass rod with a woollen cloth it get charged positivelyand when we touch the"+"charged rod with metallic disc it get +charged and the metallic sheets repel each other due to similar charges