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Old-Exam-Questions-Chapter 21-082(Dr. Naqvi- h!s102. 0"-0#$
081Q1.Particle 1 with charge q1, and particle 2 with charge
q2are on the x axis, with particle 1 atx= 4.0 cm and
particle 2 atx= 2.0 cm. Find the relationship between q1and q2so
that the net force on a third particle of charge q
located at the origin, be ero, !"ns# q2= q1 $ 4%Q2% " particle
with charge 2.0 &' is placed at the origin, an identical
particle, with the same charge, is placed 2.0
cm from the origin on the positi(e x axis, and a third identical
particle, with the same charge, is placed 2.0 cm fromthe origin on
the positi(e ) axis. *he magnit+de of the force on the particle at
the origin is# !"ns# 1. - 102%0&2 Q2./n the fig+re 1, , charge
= . n'. For what (al+e of charge q1 will charge q2 be in static
eq+ilibri+m3
!"ns# 1 n'%
'0&1Q1. Fo+r point charges, each of the same magnit+de, with
(ar)ing signs are arranged at the corners of a sq+are as
shown in the fig+re 1. 5hich of the arrows labeled ), *, C, and
D gi(es the correct direction of the net force that
acts on the charge at the +pper right corner3 !"ns# 6%Q1#. *hree
identical point charges, Q, are placed at the corners of an
eq+ilateral triangle as shown in the fig+re 2.
*he length of each side of the triangle is d. 7etermine the
magnit+de and direction of the total electrostatic force on
the charge at the top of the triangle. !"ns# 8 2$d2directed
+pward%
Q18. 'onsider two cond+cting spheres, ) and *, ha(ing the same
sie. 9phere ) carries a charge of 2.0 :' and
sphere * carries a charge of ;
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'0"2%Q1 *wo positi(el) charged particles q1 and q2 !with q2Aq1%
are fixed in place on the xaxis at the positions shown in
fig+re 1. " third charge q is to be placed somewhere on the
xaxis s+ch that the net electrostatic force on q is ero. 5hich
one
of the following statements is *BCD3 !"ns# q sho+ld be placed at
a point between q1 and q2b+t closer to q1%Q2 *wo 1.0 g spheres are
charged eq+all) and placed 2.0 cm apart. 5hen released, each one
begins to accelerate at 22
m$sEE2. 5hat is the magnit+de of the charge on each sphere3
!"ns# 1.0E10EE!% '.%'0"1% 1# 5hat is the electric force between two
protons which are separated b) 1..0E10EE!
