For a first order reaction,the concentration of reactant was reduced from $0.03 \ mol \ L^{-1}$ to $0.02 \ mol \ L^{-1}$ in $25 \ min$. What is its rate (in $mol \ L^{-1} \ s^{-1}$)?

$A$ ray of light strikes a plane mirror $M$ at an angle of $45^o$ as shown in the figure. After reflection,the ray passes through a prism of refractive index $1.5$ whose apex angle is $4^o$. The total angle through which the ray is deviated is......$^o$

$A$ sinusoidal carrier voltage of frequency $1.5\, MHz$ and amplitude $50\, V$ is amplitude modulated by a sinusoidal voltage of frequency $10\, kHz$ producing $50\%$ modulation. The lower and upper side-band frequencies in $kHz$ are

Which of the following exhibits a haplontic life cycle?

The number of natural numbers less than $1000$,in which no two digits are repeated,is:

The rate of growth of bacteria in a culture is proportional to the number of bacteria present and the bacteria count is $1000$ at $t = 0$. The number of bacteria is increased by $20 \%$ in $2 \text{ hours}$. If the population of bacteria is $2000$ after $\frac{k}{\log \left(\frac{6}{5}\right)} \text{ hours}$,then $\left(\frac{k}{\log 2}\right)^2$ is