Question Bank Directory

For the following logic gate, the truth table is:

In the given figure, the potential difference between $A$ and $B$ is:

A football player is moving southward and suddenly turns eastward with the same speed to avoid an opponent. The force that acts on the player while turning is

The binding energy per nucleon of deuterium and helium atom is 1.1 MeV and 7.0 MeV. If two deuterium nuclei fuse to form a helium atom, the energy released is:

A sample of radioactive element has a mass of 10 gm at an instant $t = 0$. The approximate mass of this element in the sample after two mean lives is:

If the radius of ${}^{27}_{13}\mathrm{Al}$ nucleus is taken to be $R_{\mathrm{Al}}$, then the radius of ${}^{125}_{53}\mathrm{Te}$ nucleus is near:

A point performs simple harmonic oscillation of period $T$ and the equation of motion is given by $x = a \sin(\omega t + \pi/6)$. After the elapse of what fraction of the time period the velocity of the point will be equal to half of its maximum velocity?

In the radioactive decay process, the negatively charged emitted β-particles are:

A certain mass of hydrogen is changed to helium by the process of fusion. The mass defect in the fusion reaction is 0.02866 u. The energy liberated per nucleon is: (given 1 u = 931 MeV)

A mixture consists of two radioactive materials $A_1$ and $A_2$ with half lives of 20 s and 10 s respectively. Initially the mixture has 40 g of $A_1$ and 160 g of $A_2$. The amount of the two in the mixture will become equal after:

Which of the following is deflected by electric field?

The half-life of a radioactive nucleus is 50 days. The time interval $(t_2 - t_1)$ between the time $t_2$ when $\frac{2}{3}$ of it has decayed and the time $t_1$ when $\frac{1}{3}$ of it had decayed is:

In the given nuclear reaction, the element X is: ${}^{22}_{11}\mathrm{Na} \rightarrow X + e^+ + \nu$

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

A parallel plate capacitor of capacitance 20 μF is being charged by a voltage source whose potential is changing at the rate of 3 V/s. The conduction current through the connecting wires, and the displacement current through the plates of the capacitor would be, respectively:

A nucleus with mass number 240 breaks into fragments each of mass number 120. The binding energy per nucleon of unfragmented nuclei is 7.6 MeV while that of fragments is 8.5 MeV. The total gain in the binding energy in the process is:

In a radioactive substance at t = 0, the number of atoms is $8 \times 10^4$. Its half-life period is 3 yr. The number of atoms equal to $1 \times 10^4$ will remain after an interval of:

When a hydrogen atom is in its first excited level, its radius is:

A body performs simple harmonic motion about $x=0$ with an amplitude $a$ and a time period $T$. The speed of the body at $x=\frac{a}{2}$ will be:

The decay constant of a radio isotope is $\lambda$. If $A_1$ and $A_2$ are its activities at times $t_1$ and $t_2$ respectively, the number of nuclei which have decayed during the time $(t_1 - t_2)$ is: