1
JEE Main 2019 (Online) 12th January Morning Slot
+4
-1
In a meter bridge, the wire of length 1 m has a non-uniform cross-section such that, the variation $${{dR} \over {d\ell }}$$ of its resistance R with length $$\ell$$ is $${{dR} \over {d\ell }}$$ $$\propto$$ $${1 \over {\sqrt \ell }}$$. Two equal resistances are connected as shown in the figure. The galvanometer has zero deflection when the jockey is at point P. What is the length AP ?

A
0.3 m
B
0.25 m
C
0.35 m
D
0.2 m
2
JEE Main 2019 (Online) 12th January Morning Slot
+4
-1
Two electric bulbs, rated at (25 W, 220 V) and (100 W, 220 V), are connected in series across a 220 V voltage source. If the 25 W and 100 W bulbs draw powers P1 and P2 respectively, then :
A
P1 = 4W, P2 = 16 W
B
P1 = 16W, P2 = 4 W
C
P1 = 9W, P2 = 16 W
D
P1 = 16W, P2 = 9 W
3
JEE Main 2019 (Online) 11th January Evening Slot
+4
-1
A galvanometer having a resistance of 20 $$\Omega$$ and 30 divisions on both sides has figure of merit 0.005 ampere/division. The resistance that should be connected in series such that it can be used as a voltmeter upto 15 volt, is:
A
120 $$\Omega$$
B
125 $$\Omega$$
C
80 $$\Omega$$
D
100 $$\Omega$$
4
JEE Main 2019 (Online) 11th January Evening Slot
+4
-1
In the circuit shown, the potential difference between A and B is :

A
6 V
B
3 V
C
2 V
D
1 V
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