I and II only
I and III only
I, II and III only
I, II, III and IV only
Correct answer is D
∴i,ii, iii and iv have correct units.
Silicon doped with aluminum and germanium doped with arsenic become?
p- and n- types respectively
n- en p- type respectively
p- type semiconductor
n- type semiconductors
Correct answer is A
When silicon, a four valency element, is doped with aluminum, a three valency element, a p-type semiconductor is produced where the major carriers are the electrons.
Thus, the correct option is p-type and n-type respectively
The bond that forms a semiconductor is?
covalent
electrovalent
ionic
metallic
Correct answer is A
No explanation has been provided for this answer.
6.6 X 10-28
1.99 X 10-27
6.60 x 10-26
1.99 x 10-25
Correct answer is D
E = HF = (hc)/λ
Eλ = hc
∴ X = hc ==6.63 x 10-34 x 108
= 1.989 x 10-25
=1.99 x 10-25
\( \frac{1}{32} \)
\( \frac{1}{16} \)
\( \frac{1}{8} \)
\( \frac{1}{4} \)
Correct answer is B
80 days = 4 half lives (i.e 4 x 20dqs = 80dq)
But the fraction always left by any radioactive material after 4 half lives is
\( \left ( \frac{1}{2} \right)^4 = \frac{1}{16} \)