NEET 2018 Question Paper Mock Test

The ratio of kinetic energy to the total energy of an electron in a Bohr orbit of the hydrogen atom, is:

An electron of mass $m$ with an initial velocity $\vec{V}=V_0\hat{i}$ ($V_0>0$) enters an electric field $\vec{E}=-E_0\hat{i}$ ($E_0=\text{constant}>0$) at $t=0$. If ${\lambda }_0$ is its de-Broglie wavelength initially, then its de-Broglie wavelength at time $t$ is:

For a radioactive material, half-life is $10$ minutes. If initially there are $600$ number of nuclei, the time taken (in minutes) for the disintegration of $450$ nuclei is:

When the light of frequency $2{\nu }_0$ (where ${\nu }_0$ is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is $v_1$. When the frequency of the incident radiation is increased to $5{\nu }_0$, the maximum velocity of electrons emitted from the same plate is $v_2$. The ratio of $v_1$ to $v_2$ is:

In the circuit shown in the figure, the input voltage $V_i$ is $20\text{V}$, $V_{BE}=0$ and $V_{CE}=0$. If $R_B=500\text{k}\Omega$ and $R_C=4\text{k}\Omega$, the values of $I_B,I_C$ and $\beta$ are given by: