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
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
3
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
A filament bulb (500 W, 100 V) is to be used in a 230 V main supply. When a resistance R is connected in series, it works perfectly and the bulb consumes 500 W. The value of R is
A
230 $$\Omega $$
B
46 $$\Omega $$
C
26 $$\Omega $$
D
13 $$\Omega $$
4
NEET 2016 Phase 2
MCQ (Single Correct Answer)
+4
-1
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