त्रिज्याओं r1 < r2 < r3 के तीन संकेंद्री गोलाकार चालक कोश (concentric spherical conducting shells) इस प्रकार व्यवस्थित हैं कि सबसे भीतरी कोश भू-सम्पर्कित (V1 = 0) है और सबसे बाहरी कोश को विभव V0 पर रखा गया है। यदि बीच वाले कोश पर कोई शुद्ध आवेश नहीं है, तो बीच वाले कोश का विभव V2 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?