Polytechnic Physics Set 11

201. The image formed by a plane mirror is always

Virtual and upright Real and inverted Virtual and inverted Real and upright

Answer: Virtual and upright

202. The imaginary line passing through the center of curvature and the pole of a spherical mirror is called

Principal center Principal axis Focal length Parallel ray

Answer: Principal axis

203. A ray parallel to the principal axis after reflection from a concave mirror passes through the

Principal focus Principal axis Radius of curvature Center of curvature

Answer: Principal focus

204. When an object is placed at infinity, the size of the image formed by a convex mirror is

Point-sized Enlarged Magnified Same size

Answer: Point-sized

205. The type of mirror used by dentists to view large images of patients’ teeth is

Concave Convex Plane Plano-convex

Answer: Concave

206. For the given pair of media, the ratio of the sine of the angle of refraction to the sine of the angle of incidence is constant. This principle is called

Moula’s principle/law Snell’s principle/law Stefan’s law/principle Pascal’s principle/law

Answer: Snell’s principle/law

207. Which of the following has the highest refractive index?

Ice Carbon Diamond Ruby

Answer: Diamond

208. The effective diameter of the circular outline of a spherical lens is called

Aperture Optical center Pole Principal focus

Answer: Aperture

209. The focal length of a plane mirror is

Zero One Infinity Two

Answer: Infinity

210. The SI unit of lens power is

Meter Diopter Centimeter Steradian

Answer: Diopter

211. The retina of the eye is

A light-sensitive layer The lens The object An aperture

Answer: A light-sensitive layer

212. By adjusting the focal length of the eye lens, the human eye can focus on objects at various distances. This is called

Presbyopia Accommodation Myopia Hyperopia

Answer: Accommodation

213. The change in focal length of the eye lens is caused by the action of

The pupil The retina Ciliary muscles Crystalline lens

Answer: Ciliary muscles

214. Reflection is used to estimate the size of an object

Elevation Depth Distance Size

Answer: Size

215. What type of mirror is used to see behind vehicles?

Concave mirror Parabolic mirror Plane mirror Convex mirror

Answer: Convex mirror

216. The reason for the twinkling of a star is

Atmospheric refraction Atmospheric diffraction Atmospheric scattering Dispersion of light by atmospheric particles

Answer: Atmospheric refraction

217. The scattering of light by colloidal particles is called

Thermal effect Balvin effect Raman effect Tyndall effect

Answer: Tyndall effect

218. The blue color of the sky and the red color of the sun at sunrise and sunset are due to

Scattering of light Reflection Thermal effect Tyndall effect

Answer: Scattering of light

219. One ampere of electric current is

1 Coulomb / 1 Second 1 Coulomb x 1 Second 2 Coulomb / 1 Second² 1 Coulomb x 1 Second²

Answer: 1 Coulomb / 1 Second

220. The potential difference between two points is equal to

Work done / Charge Charge x Work done Charge / Work done (Charge)² / Work done

Answer: Work done / Charge