Following figures show the arrangement of bar magnets in different configurations. Each magnet has magnetic dipole moment $$\overrightarrow m .$$ Which configuration has highest net magnetic dipole moment ?
A
(1)
B
(2)
C
(3)
D
(4)
2
AIPMT 2014
MCQ (Single Correct Answer)
+4
-1
A potentiometer circuit has been set up for finding the internal resistance of a given cell. The main battery, used across the potentiometer wire, has an emf of 2.0 V and a negligible internal resistance. The potentiometer wire itself is 4 m long. When the resistance R, connected across the given cell, has values of (i) infinity, (ii) 9.5 $$\Omega $$
the balancing lengths on the potentiometer wire are found to be 3 m and 2.85 m, respectively. The value of internal resistance of the cell is
A
0.25 $$\Omega $$
B
0.95 $$\Omega $$
C
0.5 $$\Omega $$
D
0.75 $$\Omega $$
3
AIPMT 2014
MCQ (Single Correct Answer)
+4
-1
Two identical long conducting wires $$AOB$$ and $$COD$$ are placed at right angle to each other, with one above other such that $$O$$ is their common point for the two. The wires carry $$I$$1 and $$I$$2 currents, respectively. Point $$P$$ is lying at distance f from $$O$$ along a direction perpendicular to the plane containing the wires. The magnetic field at the point $$P$$ will be