1
JEE Main 2019 (Online) 9th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
Drift speed of electrons, when 1.5 A of current flows in a copper wire of cross section 5 mm2, is $$\upsilon $$. If the electron density in copper is 9 $$ \times $$ 1028/m3 the value of $$\upsilon $$. in mm/s is close to (Take charge of electron to be = 1.6 $$ \times $$ 10$$-$$19C)
A
0.02
B
3
C
2
D
0.2
2
JEE Main 2018 (Online) 16th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A galvanometer with its coil resistance 25 $$\Omega $$ requires a current of 1 mA for its full deflection. In order to construct an ammeter to read upto a current of 2 A, the approximate value of the shunt resistance should be :
A
$$2.5 \times {10^{ - 3}}\,\Omega $$
B
$$1.25 \times {10^{ - 2}}\Omega $$
C
$$1.25 \times {10^{ - 3}}\Omega $$
D
$$2.5 \times {10^{ - 2}}\Omega $$
3
JEE Main 2018 (Online) 16th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
A heating element has a resistance of 100 $$\Omega $$ at room temperature. When it is connected to a supply of 220 V, a steady current of 2 A passes in it and temperature is 500oC more than room temperature. what is the temperature coefficient of resistance of the heating element ?
A
0.5 $$ \times $$ 10$$-$$4 oC$$-$$1
B
5 $$ \times $$ 10$$-$$4 oC$$-$$1
C
1 $$ \times $$ 10$$-$$4 oC$$-$$1
D
2 $$ \times $$ 10$$-$$4 oC$$-$$1
4
JEE Main 2018 (Online) 16th April Morning Slot
MCQ (Single Correct Answer)
+4
-1
Change Language
In a circuit for finding the resistance of a galvanometer by half deflection method, a 6 V battery and a high resistance of 11 k$$\Omega $$ are used. The figure of merit of the galvanometer is 60 $$\mu A/$$division. In the absence of shunt resistance, the galvanometer produces a deflection of $$\theta $$ = 9 divisions when current flows in the circuit. The value of the shunt resistance that can cause the deflection of $$\theta /2,$$ is closest to :
A
500 $$\Omega $$
B
220 $$\Omega $$
C
55 $$\Omega $$
D
110 $$\Omega $$
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