Question

A resistance is shown in the figure. Its value and tolerance are respectively given by:
(A) $27K\Omega, {\text{ }}20\% $
(B) $270K\Omega, {\text{ 5}}\% $
(C) $270K\Omega, {\text{ 1}}0\% $
(D) $27K\Omega, {\text{ 10}}\% $

Answer 1

Hint
For solving this question, we need to use the colour coding used for the carbon resistor. Both the value and the tolerance of the resistance are indicated by this colour coding.

Complete step by step answer
The colour bands on the resistance, in order from left to right, are written as
Red, violet, orange, silver. Using the colour coding for the carbon resistor, we get the values of these colours as
Red $ \to 2$
Violet $ \to 7$
Orange $ \to {10^3}$
Silver $ \to 10\% $
So, the resistance of the given resistance is $R = (27 \times {10^3} \pm 10\% ){\text{ }}\Omega $
From the above magnitude of resistance, we see that the value of the resistance is $27 \times {10^3}{\text{ }}\Omega $ or$27K\Omega $ and the tolerance is of $10\% $
Hence, the correct answer is option (D).

Additional Information
The colour coding of carbon resistor is given in the following table:

Colour	Number	Multiplier	Tolerance (%)
Black	$0$	${10^0}$
Brown	$1$	${10^1}$
Red	$2$	${10^2}$
Orange	$3$	${10^3}$
Yellow	$4$	${10^4}$
Green	$5$	${10^5}$
Blue	$6$	${10^6}$
Violet	$7$	${10^7}$
Gray	$8$	${10^8}$
White	$9$	\[{10^9}\]
Gold		${10^{ - 1}}$	$5$
Silver		${10^{ - 2}}$	$10$
No Colour			$20$

All resistances have four colour bands, and their indications are respectively given as
- Colour 1 - First significant figure
- Colour 2 - Second significant figure
- Colour 3 - Decimal multiplier
- Colour 4 – Tolerance
The colour coding of a resistor is always read in the left to right order.

Note
For solving these types of questions, we have to remember the colour coding for the carbon resistance. A simple trick to keep it on your fingertips is-
B B ROY Great Britain Very Good Wife wearing Gold Silver Necklace.
Where the letters in bold indicate the colours Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Gray, White, Gold, Silver, and No colour respectively.