Question

A) If a concave mirror makes an image such that the image is located at C , the object will be at :-
(1) At the pole (2) At the centre (3) At the focus (4) Behind the mirror

B) What are The properties of the image if an object is kept 15 cm in front of a concave mirror of R=20 cm :-
(1) Real, enlarge, Inverted (2) Virtual , inverted , erect
(3) Real, diminished , inverted (4) Virtual , diminished and erect

C) When the object is placed between Centre & Focus of a convex , image is formed
(1) At Centre (2) Between Focus & Pole (3) behind centre (4)none

D) In case of a convex mirror , image is always :-
(1)At Centre (2) between Centre and infinity (3) between Centre and focus (4) between Centre and focus

E) The site of the image is always smaller than the object in:-
(1) concave mirror (2)convex mirror (3) plane mirror (4) none

F) Which one of the following statements regarding a convex mirror is incorrect :-
(1) Always gives an erect image (2) Always gives an diminished image (3) Always gives a real image (4)None


(Please answer those MCQ) ​

Answer 1

Answer:

Question A, answer (2)

Question B , Answer (1)

Question C , Answer (2)

Question D, Answer Between F and P

Question E, Answer (2)

Question F, Answer (3)

Explanation:

Question A,

By using mirror formula $\frac{1}{v}+\frac{1}{u} = \frac{1}{f}$

given,

image location is at C, i.e, image distance  v=2f  (∵ R=2f)

Substituting the value of v in mirror formula,

$\frac{1}{2f}+\frac{1}{u} =\frac{1}{f}$

⇒ $\frac{1}{u} = \frac{1}{f} -\frac{1}{2f}$

⇒ $\frac{1}{u} = \frac{2-1}{2f}$   (LCM = 2f)

⇒ $\frac{1}{u} =\frac{1}{2f}$

⇒ u = 2f.

i.e object is also located at 2f, i.e at C.

Question B) object distance = 15 cm

R = 20 cm

⇒ f = 10 cm (∵ R=2f)

i.e, the object is located between F and C, so the image will form beyond 2f and nature is real, inverted and Enlarged.

Question C)

Convex mirror always forms virtual images, i.e behind the mirror.

Case - 1 : if the object is placed at infinity, then image will form at F

Case - 2 : If the object is located between infinity and Pole, then image will form between F and P

Question D)

Option are not correct. the right answer should be between F and P as explained in Question 3 Answer.

Question E)

The nature of image in convex mirror is always virtual and erect

size - diminished or smaller

Question F)

The convex mirror always forms virtual, erect and diminished image.