Question Bank Directory

The SI unit of universal gas constant (R) is

At some instant, the number of radioactive atoms in a sample is $N_0$ and after time $t$, the number decreases to $N$. It is found that the graphical representation $\ln N$ versus $t$ along the $y$ and $x$ axis respectively is a straight line. Then the slope of this line is:

The half-life of a radioactive substance is 20 minutes. In how much time, the activity of substance drops to $(1/16)^{th}$ of its initial value?

The ratio of nuclear densities and nuclear volumes of ${}_{26}^{56}\mathrm{Fe}$ and ${}_{2}^{4}\mathrm{He}$ are, respectively:

At any instant, two elements $X_1$ and $X_2$ have the same number of radioactive atoms. If the decay constants of $X_1$ and $X_2$ are $10\lambda$ and $\lambda$ respectively, then the time when the ratio of their atoms becomes $1/e$ will be:

Which one of the following represents forward biased circuit?

Inspite of interspecific competition in nature, which mechanism the competing species might have evolved for their survival?

When gene targetting involving gene amplification is attempted in an individual's tissue to treat disease, it is known as :

Which of the following gate is called the universal gate?

The half-life of radium is 1622 years. How long will it take for seven-eighth of a given amount of radium to decay?

Aniline gives a set of the following reactions that yielded a coloured product 'Y'. The structure of 'Y' is: (Note: Reaction scheme is missing from the provided text)

Which one of the following equations of motion represents simple harmonic motion? (where $k, k_0, k_1$ and $a$ are all positive.)

A rectangular block of mass $m$ and area of cross-section $A$ floats in a liquid of density $\rho$. If it is given a small vertical displacement from equilibrium, it undergoes oscillation with a time period $T$. Then:

A particle of mass $m$ is released from rest and follows a parabolic path as shown. Assuming that the displacement of the mass from the origin is small, which graph correctly depicts the position of the particle as a function of time?

Which of the following is not an application of PCR (Polymerase Chain Reaction)?

A particle executing simple harmonic motion has a kinetic energy of $K = K_0 \cos^2(\omega t)$. The values of the maximum potential energy and the total energy are, respectively:

The phase difference between the instantaneous velocity and acceleration of a particle executing simple harmonic motion is:

The average velocity of a particle executing SHM in one complete vibration is:

If in a p-n junction, a square input signal of $10\text{ V}$ is applied as shown, then the output across $R_L$ will be:

Which of the following plants produces seeds but not flowers: