Physics Test - ...

What is the ratio of the wavelength of photon released when the electron jumps from 5th to 4th orbit of a hydrogen atom and then from 4th to the ground state?

A car moving with a speed of \(50\)km/h can be stopped by brakes after at least \(6\)m. If the same car is moving at a speed of \(100\) km/h, the minimum stopping distance is:

A hydrogen atom emits a photon of wavelength \(1027 \stackrel{\circ}{{A}}\). Its angular momentum changes by:

The moon is observed from two diametrically opposite points \(\mathrm{A}\) and \(\mathrm{B}\) on Earth. The angle \(\theta\) subtended at the moon by the two directions of observation is \(1^{\circ} 54^{\prime}\). Given the diameter of the Earth to be about \(1.276 \times 10^{7} \mathrm{~m}\), compute the distance of the moon from the Earth.

A block of mass \(0.1 \mathrm{~kg}\) is connected to an elastic spring of spring constant \(640 \mathrm{Nm}^{-1}\) and oscillates in a damping medium of damping constant \(10^{-2} \mathrm{~kg} \mathrm{~s}^{-1}\). The system dissipates its energy gradually. The time taken for its mechanical energy of vibration to drop to half of its initial value is closest to:

In an experiment to determine the period of a simple pendulum of length \(1 \mathrm{~m}\), it is attached to different spherical bobs of radii \(\mathrm{r}_{1}\) and \(\mathrm{r}_{2}\). The two spherical bobs have uniform mass distribution. If the relative difference in the periods, is found to be \(5 \times 10^{-4} \mathrm{~s}\), the difference in radii, \(\left|\mathrm{r}_{1}-\mathrm{r}_{2}\right|\)is best given by:

Two perpendicular forces of \(8\) Newton and \(6\) Newton are applied on a body of mass \(5.0\) kg. Find the magnitude of the acceleration of the body.

A circular disc of radius \(0.2\) meter is placed in a uniform magnetic field of induction \(\frac{1}{\pi}\left(\frac{Wb}{{m}^{2}}\right)\) in such a way that its axis makes an angle of \(60^{\circ}\) with \(\overrightarrow{{B}}\). The magnetic flux linked with the disc is:

Find the amount of work done in rotating a dipole of dipole moment \(3 \times 10^{-3} \) cm from its position of stable equilibrium to the position of unstable equilibrium, in a uniform electric field of intensity \(10^{4} N C^{-1}\).