MCQ
Convex lens is used in :
  • A
    short-sightedness
  • long-sightedness
  • C
    presbyopia
  • D
    astigmatism

Answer

Correct option: B.
long-sightedness
B

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In hydrogen bomb large amount of energy is produced due to :

The magnet can be completely demagnetized by

(a) Breaking the magnet into small pieces

(b) Heating it slightly

(c) Droping it into ice cold water

(d) A reverse field of appropriate strength

$\beta$-rays are deflected in :

If a coil of metal wire is kept stationary in a non-uniform magnetic field, then

(a) An e.m.f. is induced in the coil

(b) A current is induced in the coil

(c) Neither e.m.f. nor current is induced

(d) Both e.m.f. and current is induced

Two strings A and B, made of same material, are stretched by same tension. The radius of string A is double of the radius of B. A transverse wave travels on A with speed $\nu_\text{A}$ and on B with speed $\nu_\text{B}.$ The ratio $\frac{\nu_\text{A}}{\nu_\text{B}}$ is:

  1. $\frac{1}{2}$

  2. $2$

  3. $\frac{1}{4}$

  4. $4.$

In the given figures, three paths of an $\alpha$-particle passing nearby a nucleus (N) are shown. Among these, which path will be correct?
Image

The equivalent resistance and potential difference between A and B for the circuit is respectively

(a) 4 W, 8 V

(b) 8 W, 4 V

(c) 2 W, 2 V

(d) 16 W, 8 V

Let r be the distance of a point on the axis of a magnetic dipole from its centre. The magnetic field at such a point is proportional to:
  1. $\frac{1}{\text{r}}$
  2. $\frac{1}{\text{r}^2}$
  3. $\frac{1}{\text{r}^3}$
  4. None of these.

According to Mosley's law, the frequency of a spectral line in X-ray spectrum varies as

(a) Atomic number of the element

(b) Square of the atomic number of the element

(c) Square root of the atomic number of the element

(d) Fourth power of the atomic number of the element

The mass of a neutral carbon atom in ground state is:
  1. Exact 12u
  2. Less than 12u
  3. More than 12u
  4. Depends on the form of carbon such as graphite or charcoal.