A circular loop of 20 turns carries a current of 5.0 A. If the magnetic field at the centre of the loop is 1.57 mT, the radius of the loop would be :

The metre bridge wire is made of alloys such as nichrome because they have :

The electric potential at a point P due to a point charge of \( 9 \, \mu C \) located 10 cm away from point P is

A 25 cm long solenoid with 100 turns carries a current of 3 A. The flux density at the center of the solenoid is

What is the de Broglie wavelength associated with an electron accelerated through a potential difference of 144 V?

Conductors develop electric currents in them

After 4 hours, \( \frac{1}{16} \) of the initial amount of a certain radioactive isotope remains undecayed. What is the half life of the isotope?

The term "biodiversity" was popularised by:

Read the passage carefully and answer the questions.
Amines are considered to be derivatives of ammonia obtained by replacement of hydrogen atoms with alkyl or aryl groups. They are usually prepared from nitro compounds, halides, amides, imides etc. The presence of hydrogen bonding influences its physical properties. In alkylamines, a combination of electron releasing steric and hydrogen bonding factors influences the stability of substituted ammonium cations in protic polar solvents and thus affects the basic nature of amines. Alkyl amines are found to be stronger bases than ammonia which is more basic than water. Primary and secondary amines are engaged in intermolecular association due to hydrogen bonding. This intermolecular association is more in primary amines than in secondary amines. Tertiary amines do not have intermoleulcar association due to the absenceof hydrogen atom available for hydrogen bonding. Thus, the boiling point of amines depends on hydrogen bonding. In aromatic amines, electron releasing and withdrawing groups increase and decrease their basic character. Aryl diazonium salts usually obtained from arylamine undergo replacement of the diazonium group with a variety of nucleophile. Their coupling reaction of aryl diazonium salts with phenol or arylamine results in formation of dyes.
Complete the reaction by giving the final product:
Chloroethane + ethanolic (NaCN) + LiAlH\(_4\) \(\rightarrow\) ?

The speed of water current is half the speed of a motor boat.
The motor boat travels 15 km downstream in 1 hour.
Then the time taken to return to the starting point is:

Which of the following reactions has a positive \(\Delta S^{\circ}\) value?

Match List-I with List-II

List-I (Terms)	List-II (Features)
(A) Natality	(I) Exit of individuals
(B) Mortality	(II) Entry of individuals
(C) Immigration	(III) Death rate
(D) Emigration	(IV) Birth rate

Choose the correct answer from the options given below:

Given \(X=\left[\begin{array}{cc}1 & 0 \\ -1 & 7\end{array}\right]\), then value of K if \(X^2=8 X+K I\) is :