A metal sphere X (radius small compared with separation distances) carries an initial…
PHYSICS · Multi-part · CBSE · Physics · Electric Charges and Fields · Electric Charges and Fields
Problem
A metal sphere X (radius small compared with separation distances) carries an initial charge of +12μC while mounted on an insulating stand. A second identical sphere Y is initially uncharged and mounted on a separate insulating stand several centimeters away. The following sequence is performed:
• Step 1: The two spheres are briefly connected with a thin conducting wire and then the wire is removed.
• Step 2: Without any additional connections, sphere Y is given an extra charge of −4μC by contact with a charged object.
• Step 3: Sphere X is now brought close to, but does not touch, sphere Y.
Ignore any charge leakage to the surroundings.
(a) Determine the net charge on each sphere immediately after the wire is removed in Step 1. Show your reasoning.
(b) Determine the net charge on each sphere immediately after Step 2 is complete and before the spheres are moved.
(c) Describe qualitatively the direction of the electrostatic force on sphere X when it is brought close to sphere Y in Step 3. Justify your answer using the charges you found in part (b).
(d) Suppose the insulating stand that holds sphere Y is momentarily connected to ground while sphere X remains nearby as in Step 3, and then the ground connection is removed. Predict the new net charge on sphere Y after this grounding procedure and explain your reasoning.