Class 12th

Identify A in the following chemical reaction.

Find out the major product for the below reaction.

Compound I is heated with Conc. HI to give a hydroxyl compound  A which is further heated with Zn dust to give compound B. Identify A and B.

The major product in given the reaction is

Which of the following forms of hydrogen emits low energy β - particles?

As per given figures, two spring constants k and 2k are connected to mass m. If period of oscillation in figure (a) is 3s, then the period of oscillation in figure (b) will be $\sqrt[]{x}s.$ The value of x is________.

A potentiometer wire of length 300 cm is connected in series with a resistance 780 $\Omega$ and a standard cell of emf 4V. A constant current flows through potentiometer wire. The length of the null point for cell of emf 20 mV is found to be 60 cm. The resistance of the potentiometer wire is ________ $\Omega$ .

Identify A in the given reaction.

In a coil of resistance $8\Omega ,$ the magnetic flux due to an external magnetic field varies with time as $\varphi =\frac{2}{3}\left(9-t^2\right).$ The value of total heat produced in the coil, till the flux becomes zero, will be_______J.

Three point charges of magnitude $5\mu C,0.16\mu C,and0.3\mu C$ are located at the vertices A, B, C of a right angled triangle whose sides are AB = 3cm, BC = $3\sqrt[]{2}$ and CA = 3 and point A is the right angle corner. Charge at point A experiences __________ N of electrostatic force due to the other two charges.