List of practice Questions

When an article is bleached by $SO_2$, the colour can be restored by
When an explosive shell travelling in a parabolic path under the effect of gravity explodes in the mid air, the centre of mass of the fragments will move
When ammonia and sodium hypochlorite are allowed to react,which nitrogen compound is formed ?
When alkaline earth metals dissolve in ammonia, they form coloured solution like alkali metals. Which of the following observations regarding the reaction are correct ? (i) Dilute solutions are bright blue in colour due to solvated electrons. (ii) These solutions decompose to form amides and hydrogen. (iii) From this solution the ammoniates $[M(NH_3)_6]^{2+}$ can be recovered by evaporation.
When acetylene is treated with HBr, the product is
When acidified $K_2Cr_2O_7$ solution is added to $Sn^{2+}$ salts, then $Sn^{2+}$ changes to
When $AgNO_3$ is heated strongly the products formed are
When alkyl aryl ether is heated with HI, it gives
When a thermometer is taken from the melting ice to a warm liquid, the mercury level rises to $\frac{2^{th}}{5}$ of the distance between the lower and the upper fixed points. The temperature of liquid in $K$ is
When a voltage measuring device is connected to ac mains, the meter shows the steady input voltage of $220\,V$. This means
When accessory whorls (calyx and corolla) are absent in a flower, it is called
When a solid melts there is
When a speeding bus stops suddenly, passengers are thrown forward from their seats because
When a sphere is taken to bottom of sea 1 km deep, it contracts by 0.01%. The bulk modulus of elasticity of the material of sphere is (Given, density of water $= 1 gcm^{-3})$
When a plant undergoes senescence, the nutrients may be
When a plasmolysed cell is placed in water or hypotonic solution, what happens?
When a positively charged particle enters a uniform magnetic field with uniform velocity its trajectory can be a) straight line b)a circle c) a helix
When a ring is rolling $V_1, V_2, V_3, V_4$ are velocities of top most point, lowest point, end point of horizontal diameter, center of ring respectively. The decreasing order of these velocities is
When a mixture of air and steam is passed over red hot coke, the outgoing gas is
When a mixture of NaCl and KCl is heated with cone. $H_2SO_4$ and $K_2Cr_2O_7$. The red gas obtained is
When a nucleus in an atom undergoes a radioactive decay, the electronic energy levels of the atom
When a lead storage battery is discharged
When a low flying aircraft passes overhead, we sometimes notice a slight shaking of the picture on our TV screen. This is because of between the direct signal and reflected signal
When a mass is rotating in a plane about a fixed point its angular momentum is directed along
When a metal is to be extracted from its ore and if the gangue associated with the ore is silica, then