To practice Problem-Solving Strategy 27.2 Motion in Magnetic Fields. An electron inside of a television tube moves with a speed of 2.74×107 m/s . It encounters a region with a uniform magnetic field oriented perpendicular to its trajectory. The electron begins to move along a circular arc of radius 0.190 m . What is the magnitude of the magnetic field?Part CCalculate the magnitude F of the force exerted on the electron by a magnetic field of magnitude 8.21×10−4 T oriented as described in the problem introduction. Express your answer in newtons.

The magnetic field is  

The force is  

Explanation:

From the question we are told that

   The speed of the electron is

    The radius of the circular trajectory is

Generally the magnetic force acting on the electron is equal to the centripetal  acting on the the electron , this is is mathematically represented as

Here   is the magnetic force that will cause the electron to move in a circular path  which is mathematically represented as

while   is the centripetal  force which is mathematically represented as

=>    

=>  

Here q  is the charge on an electro with value  

   and  m  is the mass of electron with value  

So

=>    

Generally when the magnetic field is the magnetic force is  

=>  

=>  

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