1
AIEEE 2004
+4
-1
Two long conductors, separated by a distance $$d$$ carry current $${I_1}$$ and $${I_2}$$ in the same direction. They exert a force $$F$$ on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to $$3d$$. The new value of the force between them is
A
$$- {{2F} \over 3}$$
B
$${F \over 3}$$
C
$$-2F$$
D
$$- {F \over 3}$$
2
AIEEE 2003
+4
-1
A particle of mass $$M$$ and charge $$Q$$ moving with velocity $$\overrightarrow v$$ describe a circular path of radius $$R$$ when subjected to a uniform transverse magnetic field of induction $$B.$$ The network done by the field when the particle completes one full circle is
A
$$\left( {{{M{v^2}} \over R}} \right)2\pi R$$
B
zero
C
$$B\,\,Q\,2\pi R$$
D
$$B\,Qv\,2\pi R$$
3
AIEEE 2003
+4
-1
A particle of charge $$- 16 \times {10^{ - 18}}$$ coulomb moving with velocity $$10m{s^{ - 1}}$$ along the $$x$$-axis enters a region where a magnetic field of induction $$B$$ is along the $$y$$-axis, and an electric field of magnitude $${10^4}V/m$$ is along the negative $$z$$-axis. If the charged particle continues moving along the $$x$$-axis, the magnitude of $$B$$ is
A
$${10^3}Wb/{m^2}$$
B
$${10^5}Wb/{m^2}$$
C
$${10^{16}}Wb/{m^2}$$
D
$${10^{ - 3}}Wb/{m^2}$$
4
AIEEE 2002
+4
-1
If a current is passed through a spring then the spring will
A
expand
B
compress
C
remains same
D
none of these
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