1
JEE Main 2020 (Online) 4th September Morning Slot
+4
-1
A battery of 3.0 V is connected to a resistor dissipating 0.5 W of power. If the terminal voltage of the battery is 2.5 V, the power dissipated within the internal resistance is :
A
0.50 W
B
0.072 W
C
0.10 W
D
0.125 W
2
JEE Main 2020 (Online) 3rd September Evening Slot
+4
-1
Two resistors 400$$\Omega$$ and 800$$\Omega$$ are connected in series across a 6 V battery. The potential difference measured by a voltmeter of 10 k$$\Omega$$ across 400 $$\Omega$$ resistor is close to :
A
2.05 V
B
1.95 V
C
2 V
D
1.8 V
3
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
Model a torch battery of length $$l$$ to be made up of a thin cylindrical bar of radius ‘a’ and a concentric thin cylindrical shell of radius ‘b’ filled in between with an electrolyte of resistivity $$\rho$$ (see figure). If the battery is connected to a resistance of value R, the maximum Joule heating in R will take place for :
A
$$R = {{2\rho } \over {\pi l}}\ln \left( {{b \over a}} \right)$$
B
$$R = {\rho \over {\pi l}}\ln \left( {{b \over a}} \right)$$
C
$$R = {\rho \over {2\pi l}}\ln \left( {{b \over a}} \right)$$
D
$$R = {\rho \over {2\pi l}}\left( {{b \over a}} \right)$$
4
JEE Main 2020 (Online) 2nd September Evening Slot
+4
-1
Out of Syllabus
A potentiometer wire PQ of 1 m length is connected to a standard cell E1. Another cell E2 of emf 1.02 V is connected with a resistance ‘r’ and switch S (as shown in figure). With switch S open, the null position is obtained at a distance of 49 cm from Q. The potential gradient in the potentiometer wire is :
A
0.04 V/cm
B
0.01 V/cm
C
0.02 V/cm
D
0.03 V/cm
EXAM MAP
Medical
NEET