JAMB - Physics (1998 - No. 30)
The displacement d produced in a glass block of thickness t and refractive index n when an object is viewed through it is
t – n
t (1 + 1/n)
t (1-1/n)
t (1/n - 1)
Explication
n = \(\frac {\text{real depth}}{\text {apparent depth}{}}\)
n = \(\frac {t}{t-d}\)
\(\frac{t - d}{1}\) = \(\frac{t}{n}\)
-d = \(\frac{t}{n}\) - t
d = - \(\frac{t}{n}\) + t
d = t - \(\frac{t}{n}\)
d =t (1 - \(\frac{1}{n}\))
n = \(\frac {t}{t-d}\)
\(\frac{t - d}{1}\) = \(\frac{t}{n}\)
-d = \(\frac{t}{n}\) - t
d = - \(\frac{t}{n}\) + t
d = t - \(\frac{t}{n}\)
d =t (1 - \(\frac{1}{n}\))