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:  Current & Current Density |
83%
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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:  Current & Current Density |
83%
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The current in a wire varies with time according to the relation i= (3+2t) A. The amount of charge passing a cross section of the wire in the time interval t=0 to t=4.0 sec would be: (where t is time in seconds)

 1 28 C 2 30.5 C 3 8 C 4 82 C
Subtopic:  Current & Current Density |
85%
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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:  Current & Current Density |
82%
From NCERT
NEET - 2020
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Drift velocity vd varies with the intensity of electric field as per the relation:

1. ${v}_{d}\propto E$

2. ${v}_{d}\propto \frac{1}{E}$

3. vd = constant

4. ${v}_{d}\propto {E}^{2}$

Subtopic:  Current & Current Density |
77%
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. $$\frac{v}{2}$$
3. $$\frac{v}{4}$$
4. $$\frac{v}{8}$$

Subtopic:  Current & Current Density |
72%
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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:  Current & Current Density |
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:  Current & Current Density |
55%
From NCERT
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If a metallic block has no potential difference applied across it, then the mean velocity of free electron is:
(T = absolute temperature of the block)

 1 proportional to T. 2 proportional to$$\sqrt{\mathrm{T}}$$ 3 zero. 4 finite but independent of temperature.
Subtopic:  Current & Current Density |
52%
From NCERT
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Which of the following graph correctly represents the variation of mobility $\left(\mathrm{\mu }\right)$ of electrons with applied electric field (E) in a metallic conductor?

 1 2 3 4
Subtopic:  Current & Current Density |
From NCERT
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