In the given figure, a diode D is connected to an external resistance R = 100 \( \Omega \) and an emf of 2.5 V. During forward bias, if the barrier potential developed across the diode is 0.6 V, the current in the circuit will be

\( (1/16) \)th of the initial amount of a certain radio-active isotope remains undecayed after two hours. The half life of the isotope would be :

Which of the following equations represents the Ampere-Maxwell law?

In a nuclear fission reaction given below, the three neutrons are released. The value of x and y are\( {}_{0}^{1}n + {}_{92}^{235}U \rightarrow {}_{56}^{x}Ba + {}_{y}^{89}Kr + 3{}_{0}^{1}n \)

The magnetic flux through a coil placed in a magnetic field is given by \( \phi = 5t^3 + 4t^2 + 2t - 5 \) Wb The resistance of the coil is 10 \( \Omega \). The induced current through the coil at \( t = 2 \) s is :

The least distance of distinct vision of a person is 50 cm. He wants to read a book placed at 25 cm. The focal length of the spectacles would be :

For transmitting a modulated signal of wave length \( \lambda \), the antenna should have minimum size:

Calculate the magnetic moment of a divalent ion in aqueous solution if its atomic number is 27.

There are 4 bulbs out of which 2 are defective. Each bulb is tested in random order till both the defective bulbs are identified. The probability that only two tests are required to identify the defective bulbs is:

The resistance of a wire is \(10 \Omega\). Its length is increased by \(10 \backslash \%\) by stretching. The new resistance of the wire will now be :

Histones are rich in amino acids -

Which of the following statements are correct?
(A) In the sinking fund a fixed amount at regular intervals is deposited.
(B) Sinking fund is a long-term account which can be closed any time.
(C) In a saving account, any amount, any time can be deposited.
(D) Sinking fund can be used only for the purpose it was created.
Choose the correct answer from the options given below :

Read the passage carefully and answer the questions
Alcohols and phenols are formed when a hydrogen atom in a hydrocarbon, aliphatic and aromatic respectively is replaced by -OH group. These are further classified on the basis of number of hydroxy groups and according to the hybridization of the carbon atom \(sp ^2\) or \(sp ^3\) to which the -OH group is attached. They find applications in industry as well as in day-to-day life. One of the most commercially obtained alcohol also known as wood spirit is obtained by destructive distillation of wood. Both alcohols and phenols are acidic in nature. The acidity of alcohols and phenols vary according to the nature of substituent(s) attached to them. Alcohols and phenols react with carboxylic acids, acid chlorides and acid anhydrides to form esters. Introduction of acetyl group in alcohols and phenols is called acetylation. Phenol undergo electrophilic aromatic substitution reaction because the -OH activates the benzene ring. It undergoes nitration, halogenation and sulphonation reactions.
Which of the following compound lacks a phenolic group?