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,
⇒ 
⇒ 
⇒ 
⇒ 
Answer:
B.convection currents in the mantle
Explanation: