Answer:
Magnetic field, B = 0.004 mT
Step-by-step explanation:
It is given that,
Charge,
![q=3* 10^(-6)\ C](https://img.qammunity.org/2020/formulas/physics/college/ycj73pab3jaai3pnl9a9piwlqq6hifv7vg.png)
Mass of charge particle,
![m=2* 10^(-6)\ C](https://img.qammunity.org/2020/formulas/physics/college/zgk5zm9x2hkn3ujakdy0zxpxw48117tohz.png)
Speed,
![v=5* 10^(6)\ m/s](https://img.qammunity.org/2020/formulas/physics/college/moh4s3ptv409g2ewprnpixorsnrqlujojf.png)
Acceleration,
![a=3* 10^(4)\ m/s^2](https://img.qammunity.org/2020/formulas/physics/college/qnd6w4y489rg7vpmja7wn53cifsnz015ol.png)
We need to find the minimum magnetic field that would produce such an acceleration. So,
![ma=qvB\ sin\theta](https://img.qammunity.org/2020/formulas/physics/college/xsuffe88ofj3050f1bk5w7ywolp4c23nqu.png)
For minimum magnetic field,
![ma=qvB](https://img.qammunity.org/2020/formulas/physics/college/e1uyyh5l6y630dl1xs5a0oe1pad1l36l5a.png)
![B=(ma)/(qv)](https://img.qammunity.org/2020/formulas/physics/college/mv1bsgvf2h30dol6l49rpflrkyw40di4qm.png)
![B=(2* 10^(-6)\ C* 3* 10^(4)\ m/s^2)/(3* 10^(-6)\ C* 5* 10^(6)\ m/s)](https://img.qammunity.org/2020/formulas/physics/college/bxccsdlhiys3xp0dx5hqki6j368m9s7jah.png)
B = 0.004 T
or
B = 4 mT
So, the magnetic field produce such an acceleration at 4 mT. Hence, this is the required solution.