Science Class 7th

301. The medium in which light travels fast is called?

A) Dense medium

B) Transparent medium

C) None of these

 

302. The medium in which light travels slow is called?

A) Dense medium

B) Transparent medium

C) None of these

303. Which of the following is more rare?

A) Air

B) Water

C) Gas

D) All of these

304. Light travels fastest in which of the following?

A) Gas

B) Solids

C) Liquids

D) Vacuum

305. Where particles of the medium are not closed, the medium is called?

A) Dense medium

B) Rare medium

C) Both ‘a’ and ‘b

306. When particles of the medium are closely packed

A) Rare medium

B) Dense medium

C) None of these

307. The bending of light from its original path is called?

A) Reflection

B) Refraction

C) None of these

308. Refraction of light occurs because of change in?

A) Speed of light

B) Nature

C) None

309. When light enters from rare medium to denser medium, it bends

A) Towards

B) Away

C) Both ‘a’ and ‘b

310. If light enters from denser medium to rare medium, it bends

A) Away

B) Towards

C) Straight

D) None

311. If incident ray falls normally to the surface of a glass slab, light will?

A) Bend away

B) Bend towards

C) Go straight

312. A brick in water tank seem much closer than it really is, because of what?

A) Reflection

B) Light

C) Refraction

D) None

313. The depth at which an object is actually lying in water is called -------depth

A) Real

B) Virtual

C) Apparent

D) Bogus

314. The depth at which an object seems to a person closer due to refraction, is called depth

A) Virtual

B) Apparent

C) Real

D) None

315. The angle of incidence, refraction and normal all lie in the plane.

A) Same

B) Different

C) None

316. Ratio of speed of light in air to its speed in transparent medium is always?

A) Variable

B) Constant

C) None

317. Ratio of speed of light to its speed in another transparent medium is called?

A) Index

B) Light index

C) Refractive index

D) None

318. Refractive index determines the degree to which a medium can light.

A) Straighten

B) Bend

C) None

319. Refractive index of air is?

A) 1.31

B) 1.0003

C) 1.4

D)  1.5

320. The refractive index of diamond is?

A) 1.5

B) 1.4

C) 2.5

D) 2.42