# A copper wire of radius $$1$$ mm contains $$10^{22}$$ free electrons per cubic metre. The drift velocity for free electrons when $$10$$ A current flows through the wire will be: (Given, charge on electron = $$1.6\times10^{-19}$$ C) 1. $$\dfrac{6.25\times10^4}{\pi}$$ m/s 2. $$\dfrac{6.25}{\pi}\times10^3$$ m/s 3. $$\dfrac{6.25}{\pi}$$ m/s 4. $$\dfrac{6.25\times10^5}{\pi}$$ m/s

Subtopic:  Current & Current Density |
71%
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NEET - 2023
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A certain wire $$A$$ has resistance $$81$$ $$\Omega$$. The resistance of another wire $$B$$ of the same material and equal length but of diameter thrice the diameter of $$A$$ will be:
 1 $$81$$ $$\Omega$$ 2 $$9$$ $$\Omega$$ 3 $$729$$ $$\Omega$$ 4 $$243$$ $$\Omega$$
Subtopic:  Derivation of Ohm's Law |
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NEET - 2023
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On the basis of electrical conductivity, which one of the following material has the smallest resistivity?
1. Germanium
2. Silver
3. Glass
4. Silicon
Subtopic:  Derivation of Ohm's Law |
62%
From NCERT
NEET - 2023
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The resistance of platinum wire at $$0^{\circ} \text{C}$$ is $$2~ \Omega$$ and $$6.8~ \Omega$$ at $$80^{\circ}\text{C}$$. The temperature coefficient of resistance of the wire is:
 1 $$(3\times 10^{-1})^\circ \text{C}^{-1}$$ 2 $$(3 \times 10^{-4})^\circ \text{C}^{-1}$$ 3 $$(3 \times 10^{-3})^\circ \text{C}^{-1}$$ 4 $$(3 \times 10^{-2})^\circ \text{C}^{-1}$$
Subtopic:  Derivation of Ohm's Law |
67%
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NEET - 2023
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The reciprocal of resistance is:
 1 reactance 2 mobility 3 conductivity 4 conductance
Subtopic:  Derivation of Ohm's Law |
79%
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NEET - 2022
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The equivalent resistance of the infinite network given below is:

1. $$2~\Omega$$
2. $$(1+\sqrt2)~\Omega$$
3. $$(1+\sqrt3)~\Omega$$
4. $$(1+\sqrt5)~\Omega$$
Subtopic:  Combination of Resistors |
53%
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NEET - 2022
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A cell of emf  $$4~\text{V}$$ and internal resistance $$0.5~\Omega$$ is connected to a $$7.5~\Omega$$ external resistance. The terminal potential difference of the cell is:
 1 $$3.75~\text{V}$$ 2 $$4.25~\text{V}$$ 3 $$4~\text{V}$$ 4 $$0.375~\text{V}$$
Subtopic:  EMF & Terminal Voltage |
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NEET - 2022
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A network of resistors is connected across a $$10~\text{V}$$ battery with an internal resistance of $$1~\Omega$$ as shown in the circuit diagram. The equivalent resistance of the circuit is:

 1 $$\dfrac{17}{3}~\Omega$$ 2 $$\dfrac{14}{3}~\Omega$$ 3 $$\dfrac{12}{7}~\Omega$$ 4 $$\dfrac{14}{7}~\Omega$$
Subtopic:  Combination of Resistors |
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NEET - 2022
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The plot of current $$I~\text{(A)}$$ flowing through a metallic conductor versus the applied voltage $$V~\text{(volt)}$$ across the ends of a conductor is:

 1 2 3 4
Subtopic:  Derivation of Ohm's Law |
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NEET - 2022
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A Wheatstone bridge is used to determine the value of unknown resistance $$\mathrm{X}$$ by adjusting the variable resistance $$\mathrm{Y}$$ as shown in the figure. For the most precise measurement of $$\mathrm{X}$$, the resistances $$\mathrm{P}$$ and $$\mathrm{Q}$$:

 1 do not play any significant role. 2 should be approximately equal to $$2\mathrm{X}$$. 3 should be approximately equal and are small. 4 should be very large and unequal.
Subtopic:  Wheatstone Bridge |
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NEET - 2022
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