A car driver going at some speed v engaged in phone call all of a sudden finds a wide wall at a distance d. Are hard brakes applied in panic or car suddenly turned in a circle of radius d more likely to avoid collision with the wall? Assume that the driving balance is not lost.
The first three spectral lines of H-atom in the Balmer series are given by $\lambda_1,\lambda_2,\lambda_3$ respectively. Considering the Bohr atomic model, the ratio of wave lengths of first and third spectral lines $\frac {\lambda_1}{\lambda_3}$ is approximately given by $’x’ \times 10^{-1}$.
The value of x, to the nearest integer is———–. Continue reading The first three spectral lines of H-atom ….
A body is executing simple harmonic motion with frequency ‘n’, the frequency of its potential energy is:
(1) n (2) 2n
(3) 3n (4) 4n Continue reading Frequency of potential energy in SHM = ?
The escape velocity from the Earth’s surface is v. The escape velocity from the surface of another planet having radius four times that of Earth and the same mass density is:
(1) v (2) 2v
(3) 3v (4) 4v Continue reading The escape velocity from the Earth’s surface is v ….
The half-life of a radioactive nuclide is 100 hours. The fraction of original activity that will remain after 150 hours would be:
(1) $\frac {1}{2}$ (2) $\frac {1}{2\sqrt 2}$
(3) $\frac {2}{3}$ (4) $\frac {2}{3\sqrt 2}$ Continue reading The half-life of a radioactive nuclide is 100 hours ….
A capacitor of capacitance ‘C’, is connected across an AC source of voltage V, given by $V=V_0 sin \omega t $. The displacement current between the plates of the capacitor, would then be given by:
(1) $I_d = V_0 \omega C cos \omega t $
(2) $I_d = \frac {V_0}{\omega C} cos \omega t $
(3) $I_d = \frac {V_0}{\omega C} sin \omega t$
(4) $I_d = V_0 \omega C sin \omega t $ Continue reading A capacitor of capacitance ‘C’, is connected ….
For a plane electromagnetic wave propagating in x-direction, which one of the following combination gives the correct possible directions for electric field (E) and magnetic field (B) respectively?
(1) $\hat j + \hat k, \hat j + \hat k $
(2) $-\hat j + \hat k, -\hat j – \hat k $
(3) $\hat j + \hat k, -\hat j – \hat k $
(4) $-\hat j + \hat k,-\hat j+\hat k $ Continue reading For a plane electromagnetic wave propagating in x-direction ….
