MENU

Chapter 15 Light Solutions

Question - 11 : -
A virtual image larger than the object can be produced by a

(i) concave lens

(ii) concave mirror

(iii) convex mirror

(iv) plane mirror

Answer - 11 : -

(ii) Concave mirror can form virtual and magnified image of the object.

Concave lens and convex mirror forms virtual but diminished image of the object. Plane mirror forms virtual and same size image of the object.

Question - 12 : -
David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be

(i) 3 m

(ii) 5 m

(iii) 6 m

(iv) 8 m

Answer - 12 : -

(iii) 6 m

In the case of a plane mirror, the distance between the object and the mirror (d1) is same as the distance between the image and the mirror (d2).
Given,

Distance between the mirror and David’s image, d2 = 4 m

Therefore, d1 = d2 = 4 m

If David moves 1 m towards the mirror, then d1 = 4 − 1 = 3 m

Again, d1 = d2 = 3 m

Therefore, the distance between David and his image is d1 + d2 = 3 + 3 = 6 m.

Question - 13 : -
The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear view mirror the image of truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be

(i) 1 m/s

(ii) 2 m/s

(iii) 4 m/s

(iv) 8 m/s

Answer - 13 : -

(iii) 4 m/s

The speed of the car is 2 m/s which means the car is approaching the truck with a speed of 2 m per second. The distance between the car and truck will decrease at a double rate. This is because the image of the truck will travel a distance twice the distance travelled by the car in equal time. Hence, the image of the truck will appear to approach the driver with the speed of 2 ×2 = 4 m/s.

Free - Previous Years Question Papers
Any questions? Ask us!
NodeJS Interview Questions Answers
ASP.Net Interview Questions Answers
Interview Questions Answers
×