Chapter 2 Electric Fields

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Chapter 2Electric The Important The Electric FieldSuppose we have a point chargeq0located atrand a set ofexternalcharges conspire so asto exert a forceFon this charge. We can define theelectric fieldat the pointrby:E=Fq0( )The (vector) value of theEfield dependsonlyon the values and locations of the externalcharges, because from Coulomb s law the force on any test charge q0is proportional to thevalue of the charge. However to make this definition really kosher we have to stipulate thatthe test chargeq0is small ; otherwise its presence will significantly influence the locationsof the external Eq. around, we can say that if the Electric field atsome pointrhas the valueEthen asmallcharge placed atrwill experience a forceF=q0E( )The Electric field is avector.

2. An electron is released from rest in a uniform electric of magnitude 2.00×104 N C. Calculate the acceleration of the electron. (Ignore gravitation.) [HRW6 23-29] The magnitude of the force on a charge q in an electricfield is givenby F = |qE|, where E is the magnitude of the field. The magnitude of the electron’s charge is e = 1.602×10 ...

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