A cell having an emf $$\varepsilon $$ and internal resistance r is connected across a variable external resistance R. As the resistance R is increased, the plot of potential difference V across R is given by
A
B
C
D
2
AIPMT 2012 Mains
MCQ (Single Correct Answer)
+4
-1
The power dissipated in the circuit shown in the figure is 30 watts. The value of R is
A
20 $$\Omega $$
B
15 $$\Omega $$
C
10 $$\Omega $$
D
30 $$\Omega $$
3
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
In the circuit shown the cells A and B have negligible resistances. For VA = 12 V, R1 = 500 $$\Omega $$ and R = 100 $$\Omega $$ the galvanometer (G) shows no deflection. The value of Vs is
A
4 V
B
2 V
C
12 V
D
6 V
4
AIPMT 2012 Prelims
MCQ (Single Correct Answer)
+4
-1
If voltage across a bulb rated 220 volt-100 watt drops by 2.5% of its rated value, the percentage of the rated value by which the power would decrease is
