डाइवर्जेंस प्रमेय का उपयोग करके व्युत्पन्न किए जाने पर गॉस का नियम यह बताता है कि किसी भी बंद सतह से बाहर आने वाला कुल विद्युत फ्लक्स Φ __________ होता है।

Which of the following statements are correct regarding electrostatic properties of conductors? A. Inside a conductor, the electrostatic field is zero. B. Electric field at the surface of a charged conductor does not depend on its surface charge density. C. The interior of a charged conductor can have no excess charge in static conditions. D. At the surface of a charged conductor, the electrostatic field must be normal to the surface at every point. E. The electrostatic potential is zero everywhere inside a charged conductor. Choose the correct answer:

What type of electric charge is acquired by a glass rod when it is rubbed with a silk cloth?