There may be an improper voltage in the device.
<u>Explanation</u>:
- Given the device has unknown circuitry and the voltage across the device crosses the voltage across the resistor at 500 Hz. In this device, the current flow is not correct. It is improper.
- The elements in the device are ammeter, capacitor, inductor, voltmeter, and battery. The components in the device may not be connected properly. This is due to the improper flow of current and condition of the voltmeter.
- So these are the type of elements in the device.
Scientists have designed solar cells to trap solar energy and convert it to D electrical energy. Its D because converting something has to do with recharging something and electronics have to charge. I hope I helped.
Answer:

and

Explanation:
See attached figure.
E due to sphere
E due to particule
(1)
according to the law of gauss and superposition Law:
; electric field due to the small sphere with r1=R/4


then:
(2)
on the other hand, for the particule:

⇒
(3)
We replace (2) y (3) in (1):


--------------------
if R<x<2R AND 

remember that 
then:

solving:


but: R<x<2R
so : 