An arrangement of three parallel straight wires placed perpendicular to plane of paper carrying same current $$'I'$$ along the same direction as shown in fogure. Magnitude of force per unit length on the middle wire $$'B'$$ is given by
A
$${{2{\mu _0}{I^2}} \over {\pi d}}$$
B
$${{\sqrt 2 {\mu _0}{I^2}} \over {\pi d}}$$
C
$${{{\mu _0}{I^2}} \over {\sqrt 2 \pi d}}$$
D
$${{{\mu _0}{I^2}} \over {2\pi d}}$$
2
NEET 2017
MCQ (Single Correct Answer)
+4
-1
If $$\theta $$1 and $$\theta $$2 be the apparent angles of dip observed in two vertical planes at right angles to each other, then the true angle of dip $$\theta $$ is given by
A 250-turn rectangular coil of length 2.1 cm and width 1.25 cm carries a current of 85 $$\mu $$A and subjected to a magnetic field of strength 0.85 T. Work done for rotating the coil by 180o against the torque is
A
4.55 $$\mu $$J
B
2.3 $$\mu $$J
C
1.15 $$\mu $$J
D
9.1 $$\mu $$J
4
NEET 2017
MCQ (Single Correct Answer)
+4
-1
Figure shows a circuit that contains three identical resistors with resistance R = 9.0 $$\Omega $$ each, two identical inductors with inductance $$L$$ = 2.0 mH each, and an ideal battery with emf $$\varepsilon = 18V$$. The current $$i$$ through the battery just after the switch closed is
