?Can Conductors be Electrified by Friction
المؤلف:
GEORGE A. HOADLEY
المصدر:
ESSENTIALS OF PHYSICS
الجزء والصفحة:
P-324
2025-11-27
14
If a brass tube is rubbed with either silk or flannel and then tested with an electroscope, no evidence of a charge will be found. This, however, is not a proof that no charge is generated; for any charge would be carried away by the body of the experimenter as fast as generated, since both the rod and the body are conductors.
Demonstration. - Flip a silk handkerchief against the knob of an electroscope and the leaves will be found to separate. The glass body of the electroscope could not carry away the charge generated. by the friction of the silk on the brass ball. Determine whether the charge is positive or, negative.
Rub a glass tube an inch or more in diameter with a silk pad. Present the knuckle to a point on the side, and take off a spark. Do this at various points along the tube. Since the glass is a nonconductor, you discharge only a small area each time.
If unlike substances are pressed together and then rapidly separated, they will become oppositely charged. This is seen in the fact that sparks can be drawn from a leather belt in running machinery, especially in dry weather.
الاكثر قراءة في الكهربائية
اخر الاخبار
اخبار العتبة العباسية المقدسة
