Polytechnic Physics Set 14

261. Arrange the following in increasing order of their refractive index.

Water, Kerosene, Glass, Diamond Kerosene, Water, Glass, Diamond Glass, Kerosene, Water, Diamond Water, Glass, Kerosene, Diamond

Answer: Water, Kerosene, Glass, Diamond

262. How is the power of a lens related to its focal length?

Directly proportional to f Directly proportional to 1/f Directly proportional to √f Directly proportional to 1/2f

Answer: Directly proportional to 1/f

263. If the power of the lens is given as +2.5D by the eye specialist, then

f = 2.5 cm, Convex lens f = 40 cm, Concave lens f = 40 cm, Convex lens f = 2.5 cm, Concave lens

Answer: f = 40 cm, Convex lens

264. The amount of light entering the human eye is controlled by?

Cornea Sclera Retina Pupil of the eye

Answer: Pupil of the eye

265. This visual defect causes the far point to come closer from infinity.

Hyperopia Cataract Myopia Presbyopia

Answer: Myopia

266. If a person reads a newspaper comfortably by holding it in front of their eyes, they have?

Cataract Presbyopia Hyperopia Myopia

Answer: Hyperopia

267. Through the refraction of white light by a glass prism, it is observed that violet bends more and red bends less, so

All colors have the same wavelength λ(violet) > λ(red) λ(red) > λ(violet) Bending does not depend on wavelength

Answer: λ(red) > λ(violet)

268. What is the color of the sky as seen from the surface of the Moon?

Red Blue White Black

Answer: Black

269. A 5 cm tall object is placed at a distance of 20 cm from a concave mirror with a focal length of 15 cm. What is the nature of the image?

Real, Inverted, Larger Real, Upright, Smaller Virtual, Inverted, Smaller Virtual, Upright, Smaller

Answer: Real, Inverted, Larger

270. Light with a wavelength of 750 nanometers enters a glass slab with a refractive index of 1.5. What is the approximate change in the wavelength of light?

500 nanometers 250 nanometers 750 nanometers 1250 nanometers

Answer: 500 nanometers

271. There are two lenses. One is a convex lens with a focal length of 20 cm, and the other is a concave lens with a focal length of 25 cm. What will be the focal length of this combination?

0.01 cm 100 cm 10 cm 1 cm

Answer: 100 cm

272. If the refractive index of water is 4/3 with respect to air, what is the refractive index of air with respect to water?

4 x 3 3/4 √(4/3) √(3/4)

Answer: 3/4

273. A person requires a lens with a power of -0.50D. What is the location of their far point?

0.5 m 4 m 2 m 1/4 m

Answer: 4 m

274. What is the near point of an eye affected by hyperopia?

25 cm < 25 cm > 25 cm At infinity

Answer: > 25 cm

275. In an electric circuit, if 1 coulomb of charge is moved from point A to point B doing 1J of work, it refers to:

1 ampere of electric current between points A and B A potential difference of 1V between points A and B A charge of 1.6 x 10⁻¹⁹ coulombs between points A and B None of the above

Answer: A potential difference of 1V between points A and B

276. According to Ohm’s law, V = IR

V α R I α R V α 1/R V α I

Answer: V α I

277. The resistance of a wire depends on which of the following factors?

Cross-sectional area Length Temperature All of the above

Answer: All of the above

278. The device used to regulate electric current in a circuit is called

Transmitter Voltmeter Current controller Galvanometer

Answer: Current controller

279. A steady potential difference is applied across a metallic conductor with an uneven cross-section. What remains constant throughout the conductor?

Electric current Resistance Electric field Current density

Answer: Electric current

280. In the circuit below, if the ammeter and voltmeter read 6A and 12V respectively, what is the value of resistance R?

> 2Ω ≥ 2Ω 2Ω < 2Ω

Answer: 2Ω