Question

In which of the following cases, the hydraulic jump is not possible?

• A. Initial speed \(>\) critical speed
• B. Initial speed \(<\) critical speed
• C. Initial speed = critical speed
• D. Independent

Hint:

Remember: - Hydraulic jump requires supercritical flow ($ V>V_c $). - If flow is subcritical ($ V<V_c $), no jump can occur.

Answer 1

The Correct Option is B

Step 1: Understand the conditions for a hydraulic jump.
A hydraulic jump occurs when the flow transitions from supercritical to subcritical. This phenomenon happens only when the initial flow velocity is greater than the critical velocity. Supercritical flow: $ V>V_c $ → shallow, fast flow
Subcritical flow: $ V<V_c $ → deep, slow flow
Critical flow: $ V = V_c $
Step 2: Analyze each option.
$ V>V_c $: Jump is possible; transition from supercritical to subcritical occurs.
$ V<V_c $: Jump is not possible; flow is already subcritical.
$ V = V_c $: Transition may occur under special conditions but is generally unstable.
"Independent": Incorrect; jump formation depends on flow condition.
Step 3: Select the correct option.
Hydraulic jump is not possible when: $$ \boxed{\text{Initial speed<critical speed}} $$