A person has near point at \(60\; cm\). The focal length of spectacles lenses to read at \(22\; cm\) having glasses separated \(2 \;cm\) from the eyes, is

A \(10\)
B \(20\)
C \(30\)
D \(40 \)

Verified Solution

Answer & Solution

Correct Answer

(C) \(30\)

Step-by-step Solution

Detailed explanation

\(u =-60\) \(v=-(22-2)=-20\)

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.

Same subject

Match List \(- I\) with List \(- II:\)

List\(-1\) (Electromagnetic waves)	List\(-2\) (Wavelength)
\((a)\) \(AM\) radio waves	\((i)\) \(10^{-10}\,m\)
\((b)\) Microwaves	\((ii)\) \(10^{2}\,m\)
\((c)\) Infrared radiations	\((iii)\) \(10^{-2}\,m\)
\((d)\) \(X-\)rays	\((iv)\) \(10^{-4}\,m\)

Choose the correct answer from the options given below:

NEET 2022 Easy

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Match the items given in Column \(I\) with those in Column \(II\) and select the correct option given below:

Column \(I\)	Column \(II\)
\((a)\)Tidal volume	\((i)\) \(2500-3000\,mL\)
\((b)\)Inspiratory Reserve volume	\((ii)\) \(1100 -1200\,mL\)
\((c)\)Expiratory Reserve volume	\((iii)\) \(500 -550\,mL\)
\((d)\) Residual volume	\((iv)\) \(1000-1100\,mL\)

NEET 2018 Medium

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