question_answer

Water rises in a capillary tube up to a length 10 cm. If the tube is inclined at \[45{}^\circ \], the length of water rises in tube will be

A) \[10\,cm\]                          

B)  \[10\sqrt{2}\,\,cm\]

C) \[\frac{10}{\sqrt{2}}\,\,cm\]                                      

D)  None of these

Correct Answer: B

Solution :

                 From the diagram                                 \[\cos {{45}^{o}}=\frac{b}{BC}=\frac{10}{BC}\] \[\Rightarrow \]               \[\frac{10}{BC}=\frac{1}{\sqrt{2}}\]                                         \[\Rightarrow \]               \[BC=10\sqrt{2}\,cm\]