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PHYSICS-IAL..JAN EXAMS..HELP pls..MAGNETIC FIELDS

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Original post by BobbJo
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resent
Original post by MARYAM1234567
resent

i)
p.d. between anode and cathode same -> accelerating p.d. same -> same kinetic energy -> v is the same as before

p.d. between plates is smaller -> E-field strength b/w plates is smaller -> Force is smaller -> deflection h is smaller

ii)
p.d between plates same, but p.d. between anode and cathode lower
so speed is decreased
so it will spend more time between the plates (t = horizontal length of plate / horizontal velocity)
so y-displacement is higher (s = 1/2at^2)
so more deflection
And also in ii) when electrons have lower speeds or the plates are longer, the electrons are going to hit the plate, since in this case all beams will touch the plate, this means the electrons with less speed will definietly defect more than the other electron beams.
Original post by BobbJo
i)
p.d. between anode and cathode same -> accelerating p.d. same -> same kinetic energy -> v is the same as before

p.d. between plates is smaller -> E-field strength b/w plates is smaller -> Force is smaller -> deflection h is smaller

ii)
p.d between plates same, but p.d. between anode and cathode lower
so speed is decreased
so it will spend more time between the plates (t = horizontal length of plate / horizontal velocity)
so y-displacement is higher (s = 1/2at^2)
so more deflection

ohhhh okay
got it ...
thanks so much!!

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