The driver of a car travelling with speed $30 \,m/s$ towards a hill sounds a horn of frequency $600 \,Hz$. If the velocity of sound in air is $330 \,m/s$,the frequency of reflected sound as heard by the driver is ........ $Hz$.

What is the name of the bond present between the units that form a disaccharide sugar?

The angle between the lines whose direction cosines satisfy the equations $l+m+n=0$ and $l^2+m^2-n^2=0$ is

Which of the following radiations has the least wavelength?

An oil drop having a mass $4.8 \times 10^{-13} ~kg$ and charge $2.4 \times 10^{-18} ~C$ stands still between two charged horizontal plates separated by a distance of $1 ~cm$. If now the polarity of the plates is changed,the instantaneous acceleration of the drop is: $(g = 10 ~ms^{-2})$ (in $~ms^{-2}$)

The $V-Q$ graph is shown below. What does the area of $\Delta OAB$ represent in this graph?