Science Class 8th

301. The expansion in length due to heating is called _____ expansion.

A) Linear

B) Perpendicular

C) Vertical

D) None of the above

302. The electric fire alarm works on the principal of _____

A) Contraction

B) Convection


C) Expansion

D) None of the above

303. The liquid expand more as compare to _____

A) Gases

B) Solids

C) Vacuum

D) None of the above

304. _____ is used in thermometer

A) Water

B) Gas

C) Mercury

D) Wine

305. When water is heated from _____ it contracts

A) 0 to 4

B) 4 to 100

C) 0 to 98

D) None the above

306. When water is cooled down from ______ it expands.

A) 100 to 4

B) 4 to 0

C) 98 to 4

D) None of the above

307. The volume of water _____ when it is heated from 0 to 4 degree

A) Decrease

B) Increase

C) Remain constant

D) Variably change

308. The volume of water _____ when it is cooled down from 4 to 0 degree.

A) Increases

B) Decreases

C) Remain constant

D) None of the above

309. The density of water is ______ at 4 degree.

A) Minimum

B) Maximum

C) Remain constant

D) None of the above

310. An instrument used for measuring temperature is called a _____

A) Thermostat

B) Thermometer

C) Thermal

D) None of the above

311. In centigrade scale, the lower standard point of temperature is ___

A) 0

B) 100

C) 32

D) 98

312. In Fahrenheit scale, the lower scale of temperature is _____

A) 32

B) 212

C) 98

D) 0

313. In Fahrenheit scale, the upper scale of temperature is _____

A) 212

B) 98

C) 32

D) 313

314. Sun is the main source of ______ A

A) Heat

B) Cool

C) Semi-heat

D) None of the above

315. Which material will expand on heating? A

A) Solids

B) Liquids

C) Gases

D) All of the these

316. Under frozen water, the aquatic life is able to survive in the water because ice act as an:

A) Conductor

B) Insulator

C) Semi-conductor

D) Condenser

317. In Fahrenheit scale, the distance between two fixed points is divided into ____ equal parts or division.

A) 100 f

B) 120 F

C) 180 F

D) 200 F

318. Heat id transferred through ____

A) Conduction

B) Convection

C) Radiation

D) All of these

319. A lens which is thick at the middle and thinner at the edge is called _____ A

A) Concave lens

B) Convex lens

C) Option A is correct

320. Convex lens is also known as a _____

A) Diverging lens

B) Concave lens

C) Converging lens

D) None of the above