Question

Fill the table

Refractive index (n)	Radius of curvature (R), m	Focal length (f), m
1.2		1.5
1.5	0.8
	1.0	1.0
1.6		0.92
1.8	1.2

Answer 1

$This\:is\:about\:Lendsmaker's\:problem.$

$This\:equation\:is\:defined\:as:$

$\frac{1}{f}=\left ( n-1 \right )\left ( \frac{1}{R_1}+\frac{1}{R_2} \right )$

$where$

$f=focal\:length$

$n=Refractive\:index$

$R_1=radius\:of\:curvature\:1$

$R_2=radius\:of\:curvature\:2$

$In\:this\:case\:\left ( by\:table \right )\:they\:consider\:just\:1\:radius\:of\:curvature.$

$Substituting\:the\:values\:from\:table:$

$1:$

$R=\left ( n-1 \right )f$

$R=\left ( 1.2-1 \right )1.5={\color{Blue} 0.3\:m}$

$2:$

$f=\frac{R}{\left ( n-1 \right )}={\color{Blue} 1.6\:m}$

$3:$

$n=\frac{R}{f}+1={\color{Blue} 2}$

$4:$

$R=\left ( n-1 \right )f={\color{Blue} 0.552\:m}$

$5:$

$f=\frac{R}{\left ( n-1 \right )}={\color{Blue} 1.5\:m}$