Class 12th

The gas 'A' is having very low reactivity reaches to stratosphere. It is non-toxic and non-flammable but dissociated by UV-radiations in stratosphere. The intermediates formed initially from the gas 'A' are:

X different wavelengths may be observed in the spectrum from a hydrogen sample if the atoms are excited to states with principal quantum number n = 6? The value of X is_______.

Out of following isomeric forms of uracil, which one is present in RNA?

On the occasion of Janmasthmi, four persons – A1, A2, A3 and A4 bought certain dozens of bananas for their respective houses. Their wives also went to the market and bought bananas. Further it is known that

I. The wives are W1, W2, W3 and W4

II. A1 bought as many bananas as his wife, A2 bought twice as many as his wife, A3 bought three times as many as his wife, and A4 bought four times as his wife.

III. W1 bought 2 dozens bananas, W2 bought 3, W3 and W4 bought 4 and 5 dozens of bananas respectively.

IV. The four couples bought 44 dozen of bananas between them.

Who is the wife of A4 among the four females?

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A): Synthesis of ethyl phenyl ether may be achieved by Williamson synthesis.

Reason (R): Reaction of bromobenzene with sodium ethoxide yields ethyl phenyl ether.

In the light of the above statements, choose the most appropriate answer from the options given below:

A capacitor of 50   $\mu F$  is connected in a circuit as shown in figure. The charge on the upper plate of the capacitor is__________   $\mu C.$

A plane electromagnetic wave with frequency of 30 MHz travels in free space. At particular point in space and time, electric field is 6 V/m. The magnetic field at this pint will be x * 10^-8T. The value of x is_______.

In the following sequence of reactions, the final product D is: