Science Class 7th

352. A white car looks white because ______ colors of white light are reflected.

A) White color

B) All colors of white

C) Green

D) Red

353. When light enters from air into glass it bends reflection

A) Towards normal

B) Away from normal

C) Doesn’t change the path

D) All the light is reflected

354. Back and forth vibration parallel to the direction of motion of wave is called?

A) Longitudinal waves

B) Transverse waves

C) Waves

D) None of these

355. _______ detects objects on or under the surface of water

A) Sonar

B) Periscope

C) Microscope

D) None

356. Sonar uses _____ propagation.

A) Sound

B) Light

C) None of these

357. Regions in longitudinal waves in which vibrating particles of medium are moving further apart and volume increases us called?

A) Compression

B) Rarefactions

C) None

 

358. In rarefaction

A) Increase in volume

B) Decrease in density occurs

C) Both ‘a’ and ‘b’

D) None

359. Regions in Longitudinal waves in which vibrating particles move closer to each other.

A) Rarefaction

B) Compression 

C) None

360. In compression,

A) Decrease in volume

B) Increase in density occurs

C) Both ‘a’ and ‘b’

361. Speed of sound in Blood at 37oC is?

A) 3140 m/s

B) 3400 m/s

C) 1570 m/s

D) None

362. Speed of sound in glass at 20oC is?

A) 3962 m/s

B) 4000 m/s

C) 3900 m/s

D) 4200 m/s

363. A wave in which particles of the medium vibrate up and down perpendicular to the direction of motion is called?

A) Longitudinal waves

B) Transverse waves

C) None

364. A rope fixed at one end and light waves are?

A) Transverse waves

B) Longitudinal waves

C) Both ‘a’ and ‘b’

D) None

365. Transverse waves can be produced in?

A) Solids

B) Liquids

C) Gases

D) Both ‘a’ and ‘b’

366. Part of transverse wave above the undisturbed position is called?

A) Trough

B) Crest

C) None of these

367. Part of transverse waves below the undisturbed position is called?

A) Trough

B) Crest

C) None

368. A distance between two consecutive trough or two consecutive crest is called?

A) Vibration

B) Wave length

C) Amplitude

D) None

369. SI unit for measuring wave length is?

A) Meter

B) Kg

C) Cd

D) None

370. The maximum displacement of the particles of the medium from their original undisturbed position is called?

A) Vibration

B) Wave length

C) Amplitude

D) None