A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is B. It is then bent into a circular coil of n turns. The magnetic field at the centre of this coil of n turns will be
A
nB
B
n2B
C
2nB
D
2n2B
2
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
An electron is moving in a circular path under the influence of a transverse magnetic field of 3.57 $$ \times $$ 10-2 T. If the value of e/m is 1.76 $$ \times $$ 1011 C kg$$-$$1, the frequency of revoluation of the electron is
A
1 GHz
B
100 MHz
C
62.8 MHz
D
6.28 MHz
3
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
The potential difference (VA $$-$$ VB) between the points A and B in the given figure is
A
$$-$$ 3V
B
+3 V
C
+6 V
D
+9 V
4
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
A parallel-plate capacitor of area a, plate separation d and capacitance C is filled with four dielectric materials having dielectric constants k1, k2, k3 and k4 as shown in the figure. If a single dielectric material is to be used to have the same capacitance C in this capacitor, then its dielectric constant k is given by