The two-dimensional motion of a particle, described by $$\vec{r}=(\hat{i}+2 \hat{j}) A \cos \omega t$$ is a/an:

A. parabolic path

B. elliptical path

C. periodic motion

D. simple harmonic motion

Choose the correct answer from the options given below:

A beam of unpolarized light of intensity I0 is passed through a polaroid A, then through another polaroid B, oriented at $$60^\circ$$ and finally through another polaroid C, oriented at 45$$^\circ$$ relative to B as shown. The intensity of emergent light is:

Select the correct statements among the following :

A. Slow neutrons can cause fission in $${ }_{92}^{235} \mathrm{U}$$ than fast neutrons.

B. $$\alpha$$-rays are Helium nuclei.

C. $$\beta$$-rays are fast moving electrons or positrons.

D. $$\gamma$$-rays are electromagnetic radiations of wavelengths larger than $$\mathrm{X}$$-rays.

Choose the most appropriate answer from the options given below :

Let $$\omega_1, \omega_2$$ and $$\omega_3$$ be the angular speed of the second hand, minute hand and hour hand of a smoothly running analog clock, respectively. If $$x_1, x_2$$ and $$x_3$$ are their respective angular distances in 1 minute then the factor which remains constant $$(k)$$ is