- 1(current)
Q. No.A uniform wire of diameter \(d\) carries a current of \(100~\text{mA}\) when the mean drift velocity of electrons in the wire is \(v.\) For a wire of diameter \({\dfrac{d}{2}}\) of the same material to carry a current of \(200~\text{mA},\) the mean drift velocity of electrons in the wire is:
| 1. | \(4v\) | 2. | \(8v\) |
| 3. | \(v\) | 4. | \(2v\) |
Subtopic: Current & Current Density |
70%
Level 2: 60%+
NEET - 2024
Hints
A uniform metal wire of length \(l\) has \(10~\Omega \) resistance. Now this wire is stretched to a length \(2l\) and then bent to form a perfect circle. The equivalent resistance across any arbitrary diameter of that circle is:
| 1. | \(10~\Omega \) | 2. | \(5~\Omega \) |
| 3. | \(40~\Omega \) | 4. | \(20~\Omega \) |
Subtopic: Current & Current Density |
50%
Level 3: 35%-60%
NEET - 2024
Hints
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)
(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 |
74%
Level 2: 60%+
NEET - 2023
Hints
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
1. \(10^{5}\) A/m2
2. \(10^{4}\) A/m2
3. \(10^{6}\) A/m2
4. \(10^{-5}\) A/m2
Subtopic: Current & Current Density |
69%
Level 2: 60%+
NEET - 2022
Hints
Match Column-I and Column-II with appropriate relations.
| Column-I | Column-II | ||
| \(\mathrm{(A)}\) | Drift Velocity | \(\mathrm{(P)}\) | \(\dfrac{{m}}{{ne}^2 \rho}\) |
| \(\mathrm{(B)}\) | Electrical Resistivity | \(\mathrm{(Q)}\) | \(nev_d\) |
| \(\mathrm{(C)}\) | Relaxation Period | \(\mathrm{(R)}\) | \(\dfrac{ {eE}}{{m}} \tau\) |
| \(\mathrm{(D)}\) | Current Density | \(\mathrm{(S)}\) | \(\dfrac{E}{J}\) |
| \(\mathrm{(A)}\) | \(\mathrm{(B)}\) | \(\mathrm{(C)}\) | \(\mathrm{(D)}\) | |
| 1. | \(\mathrm{(R)}\) | \(\mathrm{(P)}\) | \(\mathrm{(S)}\) | \(\mathrm{(Q)}\) |
| 2. | \(\mathrm{(R)}\) | \(\mathrm{(Q)}\) | \(\mathrm{(S)}\) | \(\mathrm{(P)}\) |
| 3. | \(\mathrm{(R)}\) | \(\mathrm{(S)}\) | \(\mathrm{(P)}\) | \(\mathrm{(Q)}\) |
| 4. | \(\mathrm{(R)}\) | \(\mathrm{(S)}\) | \(\mathrm{(Q)}\) | \(\mathrm{(P)}\) |
Subtopic: Current & Current Density |
58%
Level 3: 35%-60%
NEET - 2021
Hints
Links
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 |
83%
Level 1: 80%+
NEET - 2020
Hints
Links
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 |
62%
Level 2: 60%+
NEET - 2015
Hints
Links
According to the Faraday Law of electrolysis, the mass deposited at electrode will be proportional to:
1. m ∝ I2
2. m ∝ Q
3. m ∝ Q2
4. 'm' does not depend on Q
Subtopic: Current & Current Density |
76%
Level 2: 60%+
AIPMT - 2000
Hints
- 1(current)
Q. No.
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