1plz explain the 1st ques
Q1)Two positive charges +Q are held fixed a distance d apart.A particle of -ve charge -q and mass m is placed mid way between them nd thn given a small displacement perpendicular to the line joining thm nd released.The particle is in SHM,what is itz period?
Q2)The dist b/w the two plates of a cathode ray oscillograph is 1cm and potential diff b/w thm is 1200V.If an electron of energy 2000eV enters at right angles to the field.What will be its deflection if the plates be 1.5 cm long?
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4 Answers
62guys do these... not very tough.. but I am sure many of you will love to solve these...
Hint for the first one (either energy or force.. both methods will be simple)
second one : take the force or acceleration on the particle due to electric field.. You can find the electric field by the normal funda...
Then find the velocity of the elctroon.. (if you cant do post here.. i will try to reply with the complete solution.. )
1Method for first question
Total Energy = K.E + Electrostatic energy
now differentiate
0 = ∂/∂x(K.E + E.E)
in this expression,apply d2+x2≈d2
and ∂2x/∂t2 = -ω2x
from here u'll get ω and T=2π/ω
3i can give a hint for the second ques
the electron is uniformly accelerated in the negative y axis.
u can use newtons laws