The colour of the third band of a colour coded carbon resistor of resistance \( 2.3 \times 10^{2}\,\Omega \) would be:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Brown
In the colour code of a carbon resistor, the first two bands give the first two digits and the third band is the multiplier (power of ten). The colours stand for the digits black 0, brown 1, red 2, orange 3, yellow 4, green 5, blue 6, violet 7, grey 8, white 9.
Write the value with two significant digits followed by a power of ten:
\( \displaystyle 2.3\times10^{2}\,\Omega = 230\,\Omega = 23\times10^{1}\,\Omega \)
\( \text{first band: } 2 \rightarrow \text{red} \)
\( \text{second band: } 3 \rightarrow \text{orange} \)
\( \text{third band: } 10^{1} \rightarrow \text{brown} \)
Why the other options are incorrect
Option (1) Red — Incorrect. Red is the multiplier \( 10^{2} \), which gives \( 23\times10^{2} = 2300\,\Omega \); the power of ten in \( 2.3\times10^{2} \) is not the multiplier.
Option (2) Yellow — Incorrect. Yellow is the multiplier \( 10^{4} \), which gives \( 230\,\mathrm{k\Omega} \).
Option (3) Blue — Incorrect. Blue is the multiplier \( 10^{6} \), which gives \( 23\,\mathrm{M\Omega} \).
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Resistivity of Various Materials – …
