Opening of flowers in the cymose inflorescence is

The locus of the centre of a circle which passes through the origin and cuts off a chord of length $4$ units from the line $x=3$ is

$A$ wire has a resistance of $12 \, \Omega$. It is bent in the form of an equilateral triangle. The effective resistance between any two corners of the triangle is:

When acetaldehyde is heated with Fehling solution,a red precipitate is formed. Which of the following is that?

Pepsin is inactivated at $pH$

$A$ wheel is rotating at $900 \ r.p.m.$ about its axis. When the power is cut-off,it comes to rest in $1 \ minute$. The angular retardation in $rad/s^2$ is