NEET 2018 Question Paper Mock Test

A set of '$n$ ' equal resistors, of value '$R$ ' each, are connected in series to a battery of emf '$E$ ' and internal resistance '$R$ '. The current drawn is $I$. Now, the '$n$ ' resistors are connected in parallel to the same battery. Then the current drawn from battery becomes $10I$. The value of '$n$ ' is:

A battery consists of a variable number '$n$ ' of identical cells (having internal resistance '$r$ ' each) which are connected in series. The terminals of the battery are short-circuited and the current $I$ is measured. Which of the graphs shows the correct relationship between $I$ and $n$?

Unpolarised light is incident from air on a plane surface of a material of refractive index '$\mu$ '. At a particular angle of incidence '$i$ ', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?

In Young's double slit experiment the separation $d$ between the slits is $2\text{mm}$, the wavelength $\lambda$ of the light used is $5896\text{A˚}$ and distance $D$ between the screen and slits is $100\text{cm}$. It is found that the angular width of the fringes is $0.20^{\circ }$. To increase the fringe angular width to $0.21^{\circ }$ (with same $\lambda$ and $D$) the separation between the slits needs to be changed to:

An astronomical refracting telescope will have large angular magnification and high angular resolution, when it has an objective lens of: