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 2017
MCQ (Single Correct Answer)
+4
-1
The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length. its new resistance will be
A
$${R \over n}$$
B
n2R
C
$${R \over {{n^2}}}$$
D
nR
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
The potential difference (VA $$-$$ VB) between the points A and B in the given figure is
