Choose the correct alternative.

 1 Alloys of metals usually have less resistivity than that of their constituent metals. 2 Alloys usually have much higher temperature coefficients of resistance than pure metals. 3 The resistivity of the alloy manganin is nearly independent with an increase of temperature. 4 The resistivity of a typical insulator (e.g., amber) is less than that of a metal by a factor of the order of  10 22 / 10 23 .

Subtopic: Â Derivation of Ohm's Law |
Â 53%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A negligibly small current is passed through a wire of length $$15~\text{m}$$ and uniform cross-section $$6.0\times10^{-7}$$ m2, and its resistance is measured to be $$5.0~\Omega.$$ What is the resistivity of the material at the temperature of the experiment?

 1 $$1\times 10^{-7}~\Omega\text{m}$$ 2 $$2\times 10^{-7}~\Omega\text{m}$$ 3 $$3\times 10^{-7}~\Omega\text{m}$$ 4 $$1.6\times 10^{-7}~\Omega\text{m}$$
Subtopic: Â Derivation of Ohm's Law |
Â 87%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A silver wire has a resistance of $$2.1~\Omega$$ at $$27.5^\circ \text{C},$$ and a resistance of $$2.7~\Omega$$ at $$100^\circ \text{C}.$$ The temperature coefficient of resistivity of silver is:
1. $$0.0033^\circ \text{C}^{-1}$$
2. $$0.039^\circ \text{C}^{-1}$$
3. $$0.0039^\circ \text{C}^{-1}$$
4. $$0.033^\circ \text{C}^{-1}$$

Subtopic: Â Derivation of Ohm's Law |
Â 64%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints