An object with a known charge is first brought close to the ball so as to induce the opposite charge. Lets say we brought a positive object, so the ball will be negatively charged. Afterwards, the object with the unknown charge is brought closer. If the ball is attracted, then the object is positively charged and if it is repelled then the object is negatively charged.
Answer:
AM broadcasts occur on North American airwaves in the medium wave frequency range of 525 to 1705 kHz (known as the “standard broadcast band”). The band was expanded in the 1990s by adding nine channels from 1605 to 1705 kHz.
Charges added to a CONDUCTOR will immediately spread throughout the body.
Answer:
The correct solution is:
(a) 
(b) 
(c) 
(d) 
Explanation:
The given values are:
Effective duration of the flash,
ζ = 0.25 s
Average power,


Average voltage,

Now,
(a)
⇒ 
On substituting the values, we get
⇒ 
⇒ 
(b)
⇒ 
then,
⇒ 
On substituting the values, we get
⇒ 
⇒ 
(c)
⇒ 
⇒ 
⇒ 
(d)
As we know,
⇒ 
⇒ 
⇒ 
⇒ 