Wave Optics> Explain me sign convection for mirrors,le...

Explain me sign convection for mirrors,lens,and spherical surfaces in simple way...

Venky , 8 Years ago

Grade 12

3 Answers

Shreyas Patil

Last Activity: 8 Years ago

The sign convection always follows the graph sign.

Type of lens	u	v	f	Height of the image (h_I)	Height of the object (h_O)
		Real	Virtual	Real	Virtual	Real	Virtual
Convex	-	+	-	+	No virtual focus	-	+	+
Concave	-	No real image is formed	-	No real focus	-	No real image is formed	+	+

table showing sign convention of concave and convex mirrors

Hope this helps. Do approve my answer.

nath

Last Activity: 8 Years ago

Hi ! Sunkari,

for all lenses , mirror and spherical mirror the distance on the principal axis are measure from the optical centre.

The distance measure in the direction of incident rays are (+ve) and the distance measure in the direction opposite to the incident rays is (-ve).

All distance measure above the principal axis are (+ve) and measure below the principal axis are (-ve).

type u v f h_ih_o

real virtual real virtual real virtual

convex lens – + – + NO – + +

Concave lens – No – No – No + +

Convex mirror - No + + + + No +

concave || – – + – – + – +

Umakant biswal

Last Activity: 8 Years ago

@ sunkari
1- all distance from principal axis are measured from optical enter .
2-the distance measure in the direction of incident ray are +ve and opp. to that are -ve
3- all distance above the principal axis are +ve , thus height of object of an erect image are +ve
4- below the principal axis its -ve
for convex
image – +ve ( real ) , -ve ( virtual )
object – +ve (real ) , virtual – no virtual focus
height –

real (-ve ) virtual ( +ve )
height of object – always +ve .
HOPE IT CLEARS YOUR DOUBT
ALL THE BEST ..