Light of uniform intensity shines perpendicularly on a totally absorbing surface, fully illuminating the surface. If the area of the surface is decreased, what is the effect on radiation pressure ?

To obtain a n-type silicon semiconductor, it must be doped with

The physical quantity which does not change when X-rays of wavelength \( 10^{-10} \, \text{m} \), or visible light of wavelength 400 nm, or radio waves of 500 m wavelength pass through glass is

A conducting circular loop is placed in a uniform magnetic field of \( B = 0.5 \text{ T} \), with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at the rate of \( \frac{dr}{dt} = 4 \text{ mm/s} \). When the radius of the loop is \( r = 4 \text{ cm} \), the induced emf in the loop is

A voltage \( V = 200 \sin(400t) \) V AC source is connected to a series combination of an inductance 20 mH and resistance \( 6 \, \Omega \). The rms current in the AC circuit is:

Electromagnetic wave carries

The half life of a radioactive substance is 10 days. How many days will it take to disintegrate 3/4 of its initial value ?

If the matrix \(A =\left(\begin{array}{ll}1 & 3 \\ 2 & 1\end{array}\right)\), then the value of \(\operatorname{det}\left( A ^2-2 A \right)\) is equal to

Read the passage carefully and answer the following questions
Aldehydes, carboxylic acids and ketones are widespread in the animal and plant kingdoms. They play a pivotal role in various biochemical processes of life. Their presence in nature adds fragrance and flavor. These compounds are widely used in food products, pharmaceuticals, paints, resins and other important product industries. These compounds are prepared by various laboratory methods, which mainly include oxidation, formylation, acylation and reduction. Due to the polar nature of the carbonyl group in aldehydes and ketones, they can exhibit different reactions like nucleophilic addition. They do exhibit redox and various condensation reactions which lead to the formation of various important compounds. On the other hand, the carboxylic acids are mainly prepared by oxidation and hydrolysis of different compounds. The carboxylic acid consists of a carbonyl group and the hydroxy group (attached to the carbonyl carbon atom). This makes it possible for the carboxylic acid to participate in various chemical reactions which involve cleavage of the C-OH bond and the O-H bond along with the reactions involving the complete - COOH group.
Arrange the following in the increasing order of their \(p K_{ a }\) values :
(A) \(CF _3- COOH\)
(B) \(O _2 N- CH _2- COOH\)
(C) \(NC - CH _2- COOH\)
(D) \(H - COOH\)
Choose the correct answer from the options given below :

The order and degree of the differential equation \(\left(\frac{d^2 y}{d x^2}\right)^2+x^2\left(\frac{d y}{d x}\right)^3+y=\sin x\) respectively are:

Identify the correct statements for the behavior of ethane-1,2-diamine as a ligand.
(A) it is a neutral ligand
(B) it is a bidentate ligand
(C) it is an ambidentate ligand
(D) it is a chelating ligand
Choose the correct answer from the options given below:

The function \(f(x)=\frac{x}{3}+\frac{3}{x}\) is increasing in the interval:

Read the passage carefully and answer the Questions
The concentration dependence of the rate of a reaction is called the differential rate equation. It is not always convenient to determine the instantaneous rate, as it is measured by calculating the slope of the tangent at point 't' in the concentration vs time plot. This makes it difficult to determine the rate and hence the order of the reaction. This difficulty is overcome by integrating the differential rate equation. This integrated rate equation gives a direct relation between concentrations at different times and the rate constant. The integrated rate equations are different for the reactions having different reaction orders.
A certain amount of \(N _2 O _5\) decomposes to half of its initial amount in 50 minutes.
If the decomposition is a first order reaction, the rate constant of the reaction is.