AIEEE 2006 | Semiconductor Question 209 | Physics

If the ratio of the concentration of electrons to that of holes in a semiconductor is $${7 \over 5}$$ and the ratio of currents is $${7 \over 4},$$ then what is the ratio of their drift velocities?

$${5 \over 8}$$

$${4 \over 5}$$

$${5 \over 4}$$

$${4 \over 7}$$

AIEEE 2005

MCQ (Single Correct Answer)

-1

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than $$2480$$ $$nm$$ is incident on it. The band gap in $$(eV)$$ for the semiconductor is

$$2.5$$ $$eV$$

$$1.1$$ $$eV$$

$$0.7$$ $$eV$$

$$0.5$$ $$eV$$

AIEEE 2005

MCQ (Single Correct Answer)

-1

In a full wave rectifier circuit operating from $$50$$ $$Hz$$ mains frequency, the fundamental frequency in the ripple would be

$$25$$ $$Hz$$

$$50$$ $$Hz$$

$$70.7$$ $$Hz$$

$$100$$ $$Hz$$