Answer:
The value is
![B = 3.33 *10^(-6) \ T](https://img.qammunity.org/2021/formulas/physics/college/91hhx74e2ou9upw0k9vivcz8yac04hklyv.png)
Step-by-step explanation:
From the question we are told that
The distance of separation is
![d = 0.6 \ m](https://img.qammunity.org/2021/formulas/physics/college/847smaxnoudf4ig4ak7hkcj8cpkpk7a93p.png)
The current on the one wire is
![I_1 = 9 \ A](https://img.qammunity.org/2021/formulas/physics/college/nliwa53w7ttvdtsk9r9x3dvjur4rnuwyw6.png)
The current on the second wire is
![I_2 = 4 \ A](https://img.qammunity.org/2021/formulas/physics/college/lmjzver8aemvxbdsfxn78q2tmmrbhaknee.png)
Generally the magnitude of the field exerted between the current carrying wire is
![B = B_1 - B_2](https://img.qammunity.org/2021/formulas/physics/college/zk6r98r4wm4h3v3taetjtbn4sca2h1suun.png)
Here
is the magnetic field due to the first wire which is mathematically represented as
![B_1 = (\mu_o * I_1 )/(2 \pi * d_1)](https://img.qammunity.org/2021/formulas/physics/college/q0qpelpkt1zd5q2r9f9q66cwyfotsvv79h.png)
Here
is the distance to the half way point of the separation and the value is
![d_1 = 0.3 \ m](https://img.qammunity.org/2021/formulas/physics/college/azoc8ppc0zquki64qa8glt6lq4v570h71k.png)
is the magnetic field due to the first wire which is mathematically represented as
![B_2 = (\mu_o * I_2 )/(2 \pi * d_2)](https://img.qammunity.org/2021/formulas/physics/college/6rapp39sl0wut2arws9g8ypqle87d3qga2.png)
Here
is the distance to the half way point of the separation and the value is
This means that
![d_1 = d_2 = a = 0.3](https://img.qammunity.org/2021/formulas/physics/college/jd6vmtbu6w0acyfv1obrrsfho6yc6wmgj0.png)
So
![B = (\mu_o * I_1 )/(2 \pi * d_1) - (\mu_o * I_2 )/(2 \pi * d_2)](https://img.qammunity.org/2021/formulas/physics/college/wxb0nu6dw3rz3qz8b5c9dp1g0qisrbledi.png)
=>
![B = (\mu_o * (I_1 - I_2))/(2 \pi *0.3 )](https://img.qammunity.org/2021/formulas/physics/college/xec592y66zwrbdvs1sap08yrpyaseyxhai.png)
=>
![B = ( 4\pi * 10^(-7) * (9- 4))/(2 * 3.142 *0.3 )](https://img.qammunity.org/2021/formulas/physics/college/7p15wwlhs0jugz8gxaqscvcgsltgmwyyhm.png)
=>
![B = 3.33 *10^(-6) \ T](https://img.qammunity.org/2021/formulas/physics/college/91hhx74e2ou9upw0k9vivcz8yac04hklyv.png)