NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Physics
- Chapter
- Chapter
NEET 2026 · Physics · Chapter
Assertion : The thermal conductivity of metals is significantly...
Assertion : The thermal conductivity of metals is significantly higher than that of non-metals at room temperature.
Reason : In metals, a large number of free electrons are available which act as the primary carriers for the rapid transfer of thermal energy.
Reason : In metals, a large number of free electrons are available which act as the primary carriers for the rapid transfer of thermal energy.
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion.
- BIf both assertion and reason are true but reason is not the correct explanation of assertion.
- CIf assertion is true but reason is false.
- DIf both assertion and reason are false.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of assertion.
Step-by-step solution
The thermal conductivity of metals is generally much higher than that of non-metals at room temperature. This makes the assertion true.
In metals, the outermost electrons of the atoms are loosely bound and form a sea of free electrons. These free electrons are highly mobile and act as the primary carriers of thermal energy, transferring heat rapidly from the hotter region to the colder region. In non-metals, the absence of such free electrons means heat transfer occurs primarily through lattice vibrations (phonons), which is a much slower process. This makes the reason true.
The presence of free electrons is the exact cause for the high thermal conductivity of metals. Thus, the reason is the correct explanation for the assertion.
Answer: If both assertion and reason are true and reason is the correct explanation of assertion.
In metals, the outermost electrons of the atoms are loosely bound and form a sea of free electrons. These free electrons are highly mobile and act as the primary carriers of thermal energy, transferring heat rapidly from the hotter region to the colder region. In non-metals, the absence of such free electrons means heat transfer occurs primarily through lattice vibrations (phonons), which is a much slower process. This makes the reason true.
The presence of free electrons is the exact cause for the high thermal conductivity of metals. Thus, the reason is the correct explanation for the assertion.
Answer: If both assertion and reason are true and reason is the correct explanation of assertion.