The resistance of a wire is \(R\) ohm. If it is melted and stretched to \(n\) times its original length, its new resistance will be:

1. | \(nR\) | 2. | \(\frac{R}{n}\) |

3. | \(n^2R\) | 4. | \(\frac{R}{n^2}\) |

Subtopic: Derivation of Ohm's Law |

82%

From NCERT

NEET - 2017

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A wire made of a metal of uniform resistivity \(1.0\times 10^{-6}~\Omega{\text{-m}}\) is \(2.0~\text{m}\) long and has a diameter of \(2.0\times 10^{-3}~\text{m}\). What is the electrical resistance of this length of the wire?

1. \(\dfrac {2.0 ~\times~10^{-3}}{\pi} ~\Omega\)

2. \(5.0 ~\times~10^{-13}\pi~\Omega\)

3. \(\dfrac {1.0}{2\pi}~\Omega\)

4. \(\dfrac{2.0}{\pi}~\Omega\)

1. \(\dfrac {2.0 ~\times~10^{-3}}{\pi} ~\Omega\)

2. \(5.0 ~\times~10^{-13}\pi~\Omega\)

3. \(\dfrac {1.0}{2\pi}~\Omega\)

4. \(\dfrac{2.0}{\pi}~\Omega\)

Subtopic: Derivation of Ohm's Law |

82%

From NCERT

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Two solid conductors are made up of the same material and have the same length and the same resistance. One of them has a circular cross-section of area ${A}_{1}$ and the other one has a square cross-section of area ${A}_{2}$. The ratio ${A}_{1}/{A}_{2}$ is:

1. | \(1.5\) | 2. | \(1\) |

3. | \(0.8\) | 4. | \(2\) |

Subtopic: Derivation of Ohm's Law |

82%

From NCERT

NEET - 2020

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A wire of resistance \(4~\Omega\) is stretched to twice its original length. The resistance of a stretched wire would be:

1. | \(4~\Omega\) | 2. | \(8~\Omega\) |

3. | \(16~\Omega\) | 4. | \(2~\Omega\) |

Subtopic: Derivation of Ohm's Law |

82%

From NCERT

AIPMT - 2013

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The specific resistance of a conductor increases with:

1. | increase in temperature. |

2. | increase in cross-section area. |

3. | increase in cross-section and decrease in length. |

4. | decrease in cross-section area. |

Subtopic: Derivation of Ohm's Law |

79%

From NCERT

AIPMT - 2002

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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 |

79%

From NCERT

NEET - 2022

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The current-voltage graph for a given metallic conductor at two different temperatures \(T_{1}\) and \(T_{2}\) is as shown in the figure. Then:

1. | \(T_{1}=T_{2}\) | 2. | \(T_{2}>T_{1}\) |

3. | \(T_{1}>T_{2}\) | 4. | nothing can be said |

Subtopic: Derivation of Ohm's Law |

75%

From NCERT

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The dependence of resistivity \((\rho)\) on the temperature \((T)\) of a semiconductor is, roughly, represented by:

1. | 2. | ||

3. | 4. |

Subtopic: Derivation of Ohm's Law |

64%

From NCERT

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Two metal wires of identical dimensions are connected in series. If \(\sigma_1~\text{and}~\sigma_2\)

1. | \(\frac{2\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) | 2. | \(\frac{\sigma_1 +\sigma_2}{2\sigma_1\sigma_2}\) |

3. | \(\frac{\sigma_1 +\sigma_2}{\sigma_1\sigma_2}\) | 4. | \(\frac{\sigma_1 \sigma_2}{\sigma_1+\sigma_2}\) |

Subtopic: Derivation of Ohm's Law |

63%

From NCERT

NEET - 2015

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Consider a thin rectangular sheet of side \(L,\) width \(b\) and thickness \(t,\) made of a material of resistivity \(\rho\). The resistance between two opposite faces, shown by the shaded areas in the figure is:

1. | directly proportional to \(b\) |

2. | inversely proportional to \(t\) |

3. | inversely proportional to \(L\) |

4. | both (1) and (2) |

Subtopic: Derivation of Ohm's Law |

64%

From NCERT

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