Benzaldehyde reacts with ammonia to form

Which fungus has proven to be an effective biological control agent?

The end correction for the vibrations of air column in a tube of circular cross-section will be more if the tube is

The image formed by a concave mirror of focal length $6 \ cm$ is $3$ times the size of the object. The distance of the object from the mirror is......$cm$.

The work function of a substance is $4.0 \, eV$. The longest wavelength of light that can cause photoelectron emission from this substance is approximately ............ $nm$.

The magnetic flux through a circuit of resistance $R$ changes by an amount $\Delta \phi$ in time $\Delta t$. Then the total quantity of electric charge $Q$ passing during this time through any point of the circuit is given by: