A potentiometer is an accurate and versatile device to make electrical measurements of EMF because the method involves
A
potential gradients
B
a condition of no current flow through the galvanometer
C
a combination of cells, galvanometer and resistances
D
cells
2
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
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 1
MCQ (Single Correct Answer)
+4
-1
A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf's is
