- Two positive point charges each
of magnitude 10 C are xed at
positions A and B at separation
2 d = 6m. A negatively charged
particle of mass m = 90 gm
and charge of magnitude 10 × 10–6 C is revolving in a
circular path of radius 4 m in the plane perpendicular
to the line AB and bisecting the line AB. Neglect
the e ect of gravity. Find the angular velocity of
the particle.
(a) 200 rad s–1 (b) 400 rad s–1
(c) 250 rad s–1 (d) 100 rad s–1 - In rectangle shown in the
gure, the two corners
have charges q 1 = – 5 PC
and q 2 = +2.0 PC e work
done in moving a charge
of + 3.0 PC from B to A is
take^1
410
010
πε=
(a) 2.8 J (b) 3.5 J (c) 4.5 J (d) 5.5 J
- Two identical potentiometer wires w 1 and w 2 of
equal length l, connected to a battery of emf Hp
and internal resistance 1 : through two switches
S 1 and S 2. A battery of emf H is balanced on these
potentiometer wires one by one. If potentiometer
A B–q
Q Q
d dRBA5 cmq 2q 1wire w 1 is of resistance 2 : and balancing length
is l/2 on it, when only
S 1 is closed and S 2 is
open. On closing S 2
and opening S 1 t h e
balancing length on w 2
is found to be 2l/3, then
find the resistance of
potentiometer wire w 2.
(a) 0.5 : (b) 1 : (c) 0.25 : (d) 0.75 :- Assume that each atom of copper contributes one
electron. If the current owing through a copper
wire of 1 mm diameter is 1.1 A, the dri velocity of
electrons will be
(a) 0.3 mm s–1 (b) 0.5 mm s–1
(c) 0.1 mm s–1 (d) 0.2 mm s–1
(Density of Cu = 9 g cm–3, atomic weight of
Cu = 63 g) - In the circuit shown in gure, if a conducting wire is
connected between the points B and D, the current
in this wire will
(a) ow from B to D
(b) ow from D to B
(c) ow in the direction
which will be decided
by the value of V
(d) be zero
HHp :
S 2S 1w 1w 2
GVCDA(^1) :
(^4) :
4 :
3 :
B
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