If the potential difference across ends of a metallic wire is doubled, the drift velocity of charge carriers will become:
1. double
2. half
3. four times
4. one-fourth

Subtopic: Â Current & Current Density |
Â 84%
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The current in a wire varies with time according to the relation $$i = (3+2t)~\text{A}$$. The amount of charge passing a cross section of the wire in the time interval $$t=0$$ to $$t = 4.0~\text{s}$$  would be: (where $$t$$ is time in seconds)
 1 $$28$$ C 2 $$30.5$$ C 3 $$8$$ C 4 $$82$$ C
Subtopic: Â Current & Current Density |
Â 85%
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The current in a wire varies with time according to the equation $$I=(4+2t),$$ where $$I$$ is in ampere and $$t$$ is in seconds. The quantity of charge which has passed through a cross-section of the wire during the time $$t=2$$ s to $$t=6$$ s will be:

 1 $$60$$ C 2 $$24$$ C 3 $$48$$ C 4 $$30$$ C

Subtopic: Â Current & Current Density |
Â 83%
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A charged particle having drift velocity of $$7.5\times10^{-4}~\text{ms}^{-1}$$ in an electric field of $$3\times10^{-10}~\text{Vm}^{-1}$$, has mobility of:
1. $$2.5\times 10^{6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$$
2. $$2.5\times 10^{-6}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$$
3. $$2.25\times 10^{-15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$$
4. $$2.25\times 10^{15}~\text{m}^2\text{V}^{-1}\text{s}^{-1}$$

Subtopic: Â Current & Current Density |
Â 82%
From NCERT
NEET - 2020
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Drift velocity $$v_d$$ varies with the intensity of electric field as per the relation:
1. $$v_{d} \propto E$$
2. $$v_{d} \propto \frac{1}{E}$$
3. $$v_{d}= \text{constant}$$
4. $$v_{d} \propto E^2$$

Subtopic: Â Current & Current Density |
Â 78%
From NCERT
PMT - 1981
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The drift velocity of free electrons in a conductor is $$v$$ when a current $$i$$ is flowing in it. If both the radius and current are doubled, then the drift velocity will be:

 1 $$v$$ 2 $$\dfrac{v}{2}$$ 3 $$\dfrac{v}{4}$$ 4 $$\dfrac{v}{8}$$
Subtopic: Â Current & Current Density |
Â 72%
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When the potential difference applied in a conductor is doubled and also the length of the conductor is halved, the drift speed of electrons in the conductor will:
 1 not change 2 be halved 3 be four times 4 be doubled
Subtopic: Â Current & Current Density |
Â 66%
From NCERT
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A copper wire of length $$10$$ m and radius $$\left({10^{-2}/\sqrt{\pi}}\right)$$ m has an electrical resistance of $$10~\Omega.$$ The current density in the wire for an electric field strength of $$10$$ (V/m) is:
1. $$10^{5}$$ A/m2
2. $$10^{4}$$ A/m2
3. $$10^{6}$$ A/m2
4. $$10^{-5}$$ A/m2
Subtopic: Â Current & Current Density |
Â 66%
From NCERT
NEET - 2022
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Across a metallic conductor of non-uniform cross-section, a constant potential difference is applied. The quantity which remains constant along the conductor is:
 1 current density 2 current 3 drift velocity 4 electric field
Subtopic: Â Current & Current Density |
Â 59%
From NCERT
NEET - 2015
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A current passes through a wire of variable cross-section in steady-state as shown. Then incorrect statement is:

 1 Current density increases in the direction of the current. 2 Potential increases in the direction of the current. 3 Electric field increases in the direction of the current. 4 Drift speed increases in the direction of the current.

Subtopic: Â Current & Current Density |
Â 55%
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