If the standard deviation of first n natural numbers is 2, then the value of n is
The principal solutions of tan 3θ = –1 are
Two point charges q1 and q2 are ‘l’ distance apart. If one of the charges is doubled and distance between them is halved, the magnitude of force becomes n times, where n is
What is the molar mass of solute when 2.3 gram non-volatile solute dissolved in 46 gram benzene at 30°C? (Relative lowering of vapour pressure is 0.06 and molar mass of benzene is 78 gram mol–1)
What is the density of water in kgdm–3 if its density in gcm–3 is 0.863?
Identify the correct decreasing order of ease of dehydrohalogenation of alkyl halides.
To a bird in air, a fish in water appears to be at 30 cm from the surface. If refractive index of water with respect to air is \(\frac {4}{3}\) ,the real distance of bird from the surface is
Under isothermal conditions a gas expands from 0.2 dm3 to 0.8 dm3 against a constant pressure of 2 bar at 300 K. Find the work done by the gas.(1 dm3 bar = 100 J)
The objective function of L.L.P. defined over the convex set attains its optimum value at
If \(\begin{bmatrix} 2 & 1 \\ 3 & 2\end{bmatrix}\) A \(\begin{bmatrix} -3 & 2 \\ 5 & -3\end{bmatrix}\) =\(\begin{bmatrix} 1 & 0 \\ 0 & 1\end{bmatrix}\), then A =?
Time required for completion of 90% of a first order reaction is ‘t’. What is the time required for completion of 99.9%of the reaction?
If surrounding air is kept at 20 °C and body cools from 80 °C to 70 °C in 5 minutes, then the temperature of the body after 15 minutes will be
Which among the following reactions does NOT form alkyl halides?