A very small particle rests on the top of a hemisphere of radius \({20}{c}{m}\). Calculate the smallest horizontal velocity to be given to it if it is to leave the hemisphere without sliding down its surface, take \({g}={9.8}{m}/{s}^{{{2}}}\).
A cylinder of radius \({R}\) and mass \({M}\) rolls without slipping down a plane inclined at an angle \(\theta\). Coeff. of friction between the cylinder and the plane is \(\mu\). For what maximum inclination \(\theta\), the cylinder rolls without slipping ? (A) \({{\tan}^{{-{1}}}\mu}\) (B) \({{\tan}^{{-{1}}}{\left({3}\mu\right)}}\) (C) \({{\tan}^{{-{1}}}{2}}\mu\) (D) \({{\tan}^{{-{1}}}.}\frac{{{3}}}{{{2}}}\mu\)
What volume of \({3}\) molar \({H}{N}{O}_{{{3}}}\) is needed to oxidise \({8}{g}\) of \({F}{e}^{{{3}+}}\), \({H}{N}{O}_{{{3}}}\) gets converted to \({N}{O}\) ? (A) \({8}{m}{L}\) (B) \({16}{m}{L}\) (C) \({32}{m}{L}\) (D) \({64}{m}{L}\)
One mole of \({N}_{{{2}}}{H}_{{{4}}}\) loses ten moles of electrons to form a new compound \({A}\). Assuming that all the nitrogen appears in the new compound, what is the oxidation state of nitrogen in \({A}\)? (There is no change in the oxidation state of hydrogen.)
A man throws the bricks to a height of 12 m where they reach with a speed of \({12}{m}/{s}\). If he throws the bricks such that they just reach that height, what percentage of energy will be saved? \({\left({g}={9.8}{m}/{s}^{{{2}}}\right)}\) (A) \({9.5}\%\) (B) \({19}\%\) (C) \({38}\%\) (D) \({76}\%\)
A fall in glomerular filtration rate (GFR) activates (A) adrenal medulla to release adrenaline (B) anterior pituitary to release vasopressin (C) juxta glomerular cells to release renin (D) adrenal cortex to release aldosterone
The number of d-electrons in \({F}{e}^{{{2}+}}{\left({Z}={26}\right)}\) is not equal to that of : (A) p-electrons in \({N}{e}{\left({Z}={10}\right)}\) (B) p-electrons in \({M}{e}{\left({Z}={12}\right)}\) (C) p-electrons in \({F}{e}{\left({Z}={26}\right)}\) (D) p-electrons in \({C}{l}{\left({Z}={17}\right)}\)
Which one is reversible process? (A) Melting of ice at \({10}^{{\circ}}{C}\) (B) Mixing of two gases (C) Evaporation of water at \({100}^{{\circ}}{C}\) and \({1}{a}{t}{m}\) pressure (D) none of these
Is it possible for a weak acid, say acetic acid \({\left({K}_{{{a}}}={1.8}\times{10}^{{-{5}}}\right)}\) to have a pH = 7 by adding any other chemical and if so how much amount of it should be added ?