Answer:
The value is 
Explanation:
From the question we are told that
The length of the wire is 
The current density is 
The conductivity is
Generally conductivity is mathematically represented as

Here R is the resistance which is mathematically represented as

Here I is the current which is mathematically represented as

So

And

=> 
=> 
=> 
=> 
Answer:
volt ÷ ampere
Explanation:
The mathematical form of Ohms law is given by :
V = IR
Where V is voltage
I is current
R is resistance

The unit of voltage is volt and that of current is ampere
Unit of resistance :

So, volt ÷ ampere is the same as the unit of resistance. Hence, the correct option is (a).
First we need to find the speed of the dolphin sound wave in the water. We can use the following relationship between frequency and wavelength of a wave:

where
v is the wave speed

its wavelength
f its frequency
Using

and

, we get

We know that the dolphin sound wave takes t=0.42 s to travel to the tuna and back to the dolphin. If we call L the distance between the tuna and the dolphin, the sound wave covers a distance of S=2 L in a time t=0.42 s, so we can write the basic relationship between space, time and velocity for a uniform motion as:

and since we know both v and t, we can find the distance L between the dolphin and the tuna:
Current is defined as the rate of charge flowing a point every second. Having a current of 1 Ampere signifies 1 Coulomb is flowing in a circuit every second. It is measured by the use of an ammeter which is positioned in series to the component to be measured. The current in the problem is calculated as follows:
I = 2.0 x 10^-4 C / 5.0 x 10^-5 s
<span>I = 4 A</span>