1
NEET 2019
+4
-1
A 800 turn coil of effective area 0.05 m2 is kept. perpendicular to a magnetic filed 5 × 10–5 T. When the plane of the coil is rotated by 90o around any of its coplanar axis in 0.1 s, the emf induced in the coil will be :
A
0.2 V
B
0.02 V
C
2 V
D
2 $$\times$$ 10-3 V
2
NEET 2019
+4
-1
In which of the following devices, the eddy current effect is not used?
A
magnetic braking in train
B
electromagnet
C
electric heater
D
induction furnace
3
NEET 2017
+4
-1
A long solenoid of diameter 0.1 m has 2 $$\times$$ 104 turns per meter. At the centre of the solenoid, a coil of 100 turns and radius 0.01 m is placed with its axis coinciding with the solenoid axis. The current in the solenoid reduces at a constant rate to 0 A from 4 A in 0.05 s. If the resistance of the coil is 10 $$\pi$$2 $$\Omega$$, the total charge flowing through the coil during this time is
A
16 $$\mu$$C
B
32 $$\mu$$C
C
16$$\pi$$ $$\mu$$C
D
32$$\pi$$ $$\mu$$C
4
NEET 2016 Phase 2
+4
-1
A uniform magnetic field is restricted within a region of rafius r. The magnetic field changes with time at a rate $${{d\overrightarrow B } \over {dt}}$$. Loop 1 of radius R > r encloses the region r and loop 2 of radius R is outside the region of magnetic field as shown in the figure. Then the e.m.f. generated is

A
zero in loop 1 and zero in loop 2
B
$$- {{d\overrightarrow B } \over {dt}}\pi {r^2}$$ in loop 1 and $$- {{d\overrightarrow B } \over {dt}}\pi {r^2}$$ in loop 2
C
$$- {{d\overrightarrow B } \over {dt}}\pi {R^2}$$ in loop 1 and zero in loop 2
D
$$- {{d\overrightarrow B } \over {dt}}\pi {r^2}$$ in loop 1 and zero in loop 2
EXAM MAP
Medical
NEET