OnlineCBT
Physics · PYQ NEET UG 2016(1)
हिन्दीA uniform rope of length \( L \) and mass \( m_1 \) hangs vertically from a rigid support. A block of mass \( m_2 \) is attached to the free end of the rope. A transverse pulse of wavelength \( \lambda_1 \) is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is \( \lambda_2 \). The ratio \( \frac{\lambda_2}{\lambda_1} \) is
Correct answer · Option 2
\(\sqrt{\frac{m_1 + m_2}{m_2}}\)
Explanation
Speed of transverse wave \( v = \sqrt{\frac{T}{\mu}} \). At bottom \( T_1 = m_2 g \), at top \( T_2 = (m_1 + m_2)g \). Since \( v \propto \lambda \), \( \frac{\lambda_2}{\lambda_1} = \sqrt{\frac{T_2}{T_1}} = \sqrt{\frac{m_1 + m_2}{m_2}} \).
