Answer:
I = 6.42 A
Explanation:
Given that,
Potential difference, V = 0.9 V
Length of the wire, l = 1.5 m
Area of cross section, 
We need to find the current in the wire. Let I is current. We can find it using Ohm's law as follows :
V = IR
Where R is the resistance of the wire

So, the current in the wire is 6.42 A.
Explanation:
The general equation of an AC current is given by :

Where
I₀ is the peak value of current
is angular frequency

So,

We know that,

So, the frequency is 50 Hz and the maximum rms value of current is 14.14 A.
Answer:
d. lower than the original pitch and decreasing as he falls.
Explanation:
As per the Doppler effect when the pitch of the sound increases as the source approaches the observer and decreases as the source moves away. A classic example of this increasing pitch of ambulance siren as it approaches you and decreasing pitch of the siren as it goes away from you.
The same effect is applicable here as well. As the character keep falling, it is moving away from the observer so the pitch of his scream will keep on decreasing.