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PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365562 In $p$ -type semiconductor, conduction is due to

1 Greater number of holes and less number of electrons

2 Only electrons

3 Only holes

4 Greater number of electrons and less number of holes

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365563 In which of the following statements, the obtained impure semiconductor is of $p$ - type?

1 Germanium is doped with bismuth

2 Silicon is doped with antimony

3 Germanium is doped with gallium

4 Silicon is doped with phosphorus

Explanation:

$p$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with trivalent elements like Boron( $B$ ), Aluminium ( $A l$ ), Gallium ( $G a$ ), Indium ( $I n$ ) etc.
$n$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with pentavalent elements like Arsenic ( $A s$ ), Antimony ( $S b$ ), Bismuth ( $B i$ ), Phosphorus ( $P$ ) etc.

KCET - 2013

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365564 In semiconductor, the concentrations of electrons and holes are $8 \times 10^{18} m^{- 3}$ and $5 \times 10^{18} m^{- 3}$ respectively. If the mobilities of electrons and holes are $2.3 m^{2} V^{- 1} s^{- 1}$ and $0.01 m^{2} V^{- 1} s^{- 1}$ respectively, then semiconductor is

1

n -

type and its resistivity is

2.95 Ω - m

2

p -

type and its resistivity is

0.034 Ω - m

3

n -

type and its resistivity is

0.34 Ω - m

4

p -

type and its resistivity is

3.4 Ω - m

Explanation:

As, $n_{e} > h_{h}$ , so semiconductor is $n - t y p e .$
Also, conductivity $(σ) = \frac{1}{resistivity (ρ)}$
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$
$= 1.6 \times 10^{- 19}$
$\times [8 \times 10^{18} \times 2.3 + 5 \times 10^{18} \times 0.01]$
$= 2.95 Ω - m$
So, $ρ = \frac{1}{σ} = \frac{1}{2.95} = 0.34 Ω - m$

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365565 Would there be any advantage to add $n$ -type or $p$ -type impurities to copper?

1 Yes

2 No

3 May be

4 Information is insufficient

Explanation:

Pure $C u$ is already an excellent conductor, since it has a partially filled conduction band.
Further more, $C u$ forms a metallic crystal as compared to the covalent crystals of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper.
In fact adding impurities to copper decreases the conductivity, because an impurity tends to scatter electrons, impeding the flow of current
.So, there is no advantage of adding $n$ -type or $p$ -type impurities to copper.

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365566 $n$ -type semiconductor is

1 Negatively charged

2 Positively charged

3 Neutral

4 May be positive or negative

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365562 In $p$ -type semiconductor, conduction is due to

1 Greater number of holes and less number of electrons

2 Only electrons

3 Only holes

4 Greater number of electrons and less number of holes

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365563 In which of the following statements, the obtained impure semiconductor is of $p$ - type?

1 Germanium is doped with bismuth

2 Silicon is doped with antimony

3 Germanium is doped with gallium

4 Silicon is doped with phosphorus

Explanation:

$p$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with trivalent elements like Boron( $B$ ), Aluminium ( $A l$ ), Gallium ( $G a$ ), Indium ( $I n$ ) etc.
$n$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with pentavalent elements like Arsenic ( $A s$ ), Antimony ( $S b$ ), Bismuth ( $B i$ ), Phosphorus ( $P$ ) etc.

KCET - 2013

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365564 In semiconductor, the concentrations of electrons and holes are $8 \times 10^{18} m^{- 3}$ and $5 \times 10^{18} m^{- 3}$ respectively. If the mobilities of electrons and holes are $2.3 m^{2} V^{- 1} s^{- 1}$ and $0.01 m^{2} V^{- 1} s^{- 1}$ respectively, then semiconductor is

1

n -

type and its resistivity is

2.95 Ω - m

2

p -

type and its resistivity is

0.034 Ω - m

3

n -

type and its resistivity is

0.34 Ω - m

4

p -

type and its resistivity is

3.4 Ω - m

Explanation:

As, $n_{e} > h_{h}$ , so semiconductor is $n - t y p e .$
Also, conductivity $(σ) = \frac{1}{resistivity (ρ)}$
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$
$= 1.6 \times 10^{- 19}$
$\times [8 \times 10^{18} \times 2.3 + 5 \times 10^{18} \times 0.01]$
$= 2.95 Ω - m$
So, $ρ = \frac{1}{σ} = \frac{1}{2.95} = 0.34 Ω - m$

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365565 Would there be any advantage to add $n$ -type or $p$ -type impurities to copper?

1 Yes

2 No

3 May be

4 Information is insufficient

Explanation:

Pure $C u$ is already an excellent conductor, since it has a partially filled conduction band.
Further more, $C u$ forms a metallic crystal as compared to the covalent crystals of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper.
In fact adding impurities to copper decreases the conductivity, because an impurity tends to scatter electrons, impeding the flow of current
.So, there is no advantage of adding $n$ -type or $p$ -type impurities to copper.

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365566 $n$ -type semiconductor is

1 Negatively charged

2 Positively charged

3 Neutral

4 May be positive or negative

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365562 In $p$ -type semiconductor, conduction is due to

1 Greater number of holes and less number of electrons

2 Only electrons

3 Only holes

4 Greater number of electrons and less number of holes

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365563 In which of the following statements, the obtained impure semiconductor is of $p$ - type?

1 Germanium is doped with bismuth

2 Silicon is doped with antimony

3 Germanium is doped with gallium

4 Silicon is doped with phosphorus

Explanation:

$p$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with trivalent elements like Boron( $B$ ), Aluminium ( $A l$ ), Gallium ( $G a$ ), Indium ( $I n$ ) etc.
$n$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with pentavalent elements like Arsenic ( $A s$ ), Antimony ( $S b$ ), Bismuth ( $B i$ ), Phosphorus ( $P$ ) etc.

KCET - 2013

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365564 In semiconductor, the concentrations of electrons and holes are $8 \times 10^{18} m^{- 3}$ and $5 \times 10^{18} m^{- 3}$ respectively. If the mobilities of electrons and holes are $2.3 m^{2} V^{- 1} s^{- 1}$ and $0.01 m^{2} V^{- 1} s^{- 1}$ respectively, then semiconductor is

1

n -

type and its resistivity is

2.95 Ω - m

2

p -

type and its resistivity is

0.034 Ω - m

3

n -

type and its resistivity is

0.34 Ω - m

4

p -

type and its resistivity is

3.4 Ω - m

Explanation:

As, $n_{e} > h_{h}$ , so semiconductor is $n - t y p e .$
Also, conductivity $(σ) = \frac{1}{resistivity (ρ)}$
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$
$= 1.6 \times 10^{- 19}$
$\times [8 \times 10^{18} \times 2.3 + 5 \times 10^{18} \times 0.01]$
$= 2.95 Ω - m$
So, $ρ = \frac{1}{σ} = \frac{1}{2.95} = 0.34 Ω - m$

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365565 Would there be any advantage to add $n$ -type or $p$ -type impurities to copper?

1 Yes

2 No

3 May be

4 Information is insufficient

Explanation:

Pure $C u$ is already an excellent conductor, since it has a partially filled conduction band.
Further more, $C u$ forms a metallic crystal as compared to the covalent crystals of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper.
In fact adding impurities to copper decreases the conductivity, because an impurity tends to scatter electrons, impeding the flow of current
.So, there is no advantage of adding $n$ -type or $p$ -type impurities to copper.

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365566 $n$ -type semiconductor is

1 Negatively charged

2 Positively charged

3 Neutral

4 May be positive or negative

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365562 In $p$ -type semiconductor, conduction is due to

1 Greater number of holes and less number of electrons

2 Only electrons

3 Only holes

4 Greater number of electrons and less number of holes

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365563 In which of the following statements, the obtained impure semiconductor is of $p$ - type?

1 Germanium is doped with bismuth

2 Silicon is doped with antimony

3 Germanium is doped with gallium

4 Silicon is doped with phosphorus

Explanation:

$p$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with trivalent elements like Boron( $B$ ), Aluminium ( $A l$ ), Gallium ( $G a$ ), Indium ( $I n$ ) etc.
$n$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with pentavalent elements like Arsenic ( $A s$ ), Antimony ( $S b$ ), Bismuth ( $B i$ ), Phosphorus ( $P$ ) etc.

KCET - 2013

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365564 In semiconductor, the concentrations of electrons and holes are $8 \times 10^{18} m^{- 3}$ and $5 \times 10^{18} m^{- 3}$ respectively. If the mobilities of electrons and holes are $2.3 m^{2} V^{- 1} s^{- 1}$ and $0.01 m^{2} V^{- 1} s^{- 1}$ respectively, then semiconductor is

1

n -

type and its resistivity is

2.95 Ω - m

2

p -

type and its resistivity is

0.034 Ω - m

3

n -

type and its resistivity is

0.34 Ω - m

4

p -

type and its resistivity is

3.4 Ω - m

Explanation:

As, $n_{e} > h_{h}$ , so semiconductor is $n - t y p e .$
Also, conductivity $(σ) = \frac{1}{resistivity (ρ)}$
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$
$= 1.6 \times 10^{- 19}$
$\times [8 \times 10^{18} \times 2.3 + 5 \times 10^{18} \times 0.01]$
$= 2.95 Ω - m$
So, $ρ = \frac{1}{σ} = \frac{1}{2.95} = 0.34 Ω - m$

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365565 Would there be any advantage to add $n$ -type or $p$ -type impurities to copper?

1 Yes

2 No

3 May be

4 Information is insufficient

Explanation:

Pure $C u$ is already an excellent conductor, since it has a partially filled conduction band.
Further more, $C u$ forms a metallic crystal as compared to the covalent crystals of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper.
In fact adding impurities to copper decreases the conductivity, because an impurity tends to scatter electrons, impeding the flow of current
.So, there is no advantage of adding $n$ -type or $p$ -type impurities to copper.

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365566 $n$ -type semiconductor is

1 Negatively charged

2 Positively charged

3 Neutral

4 May be positive or negative

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365562 In $p$ -type semiconductor, conduction is due to

1 Greater number of holes and less number of electrons

2 Only electrons

3 Only holes

4 Greater number of electrons and less number of holes

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365563 In which of the following statements, the obtained impure semiconductor is of $p$ - type?

1 Germanium is doped with bismuth

2 Silicon is doped with antimony

3 Germanium is doped with gallium

4 Silicon is doped with phosphorus

Explanation:

$p$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with trivalent elements like Boron( $B$ ), Aluminium ( $A l$ ), Gallium ( $G a$ ), Indium ( $I n$ ) etc.
$n$ - type semiconductor is obtained when silicon ( $S i$ ) or germanium ( $G e$ ) is doped with pentavalent elements like Arsenic ( $A s$ ), Antimony ( $S b$ ), Bismuth ( $B i$ ), Phosphorus ( $P$ ) etc.

KCET - 2013

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365564 In semiconductor, the concentrations of electrons and holes are $8 \times 10^{18} m^{- 3}$ and $5 \times 10^{18} m^{- 3}$ respectively. If the mobilities of electrons and holes are $2.3 m^{2} V^{- 1} s^{- 1}$ and $0.01 m^{2} V^{- 1} s^{- 1}$ respectively, then semiconductor is

1

n -

type and its resistivity is

2.95 Ω - m

2

p -

type and its resistivity is

0.034 Ω - m

3

n -

type and its resistivity is

0.34 Ω - m

4

p -

type and its resistivity is

3.4 Ω - m

Explanation:

As, $n_{e} > h_{h}$ , so semiconductor is $n - t y p e .$
Also, conductivity $(σ) = \frac{1}{resistivity (ρ)}$
$σ = e (n_{e} μ_{e} + n_{h} μ_{h})$
$= 1.6 \times 10^{- 19}$
$\times [8 \times 10^{18} \times 2.3 + 5 \times 10^{18} \times 0.01]$
$= 2.95 Ω - m$
So, $ρ = \frac{1}{σ} = \frac{1}{2.95} = 0.34 Ω - m$

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365565 Would there be any advantage to add $n$ -type or $p$ -type impurities to copper?

1 Yes

2 No

3 May be

4 Information is insufficient

Explanation:

Pure $C u$ is already an excellent conductor, since it has a partially filled conduction band.
Further more, $C u$ forms a metallic crystal as compared to the covalent crystals of silicon or germanium, so the scheme of using an impurity to donate or accept an electron does not work for copper.
In fact adding impurities to copper decreases the conductivity, because an impurity tends to scatter electrons, impeding the flow of current
.So, there is no advantage of adding $n$ -type or $p$ -type impurities to copper.

PHXII14:SEMICONDUCTOR ELECTRONICS- MATERIALS- DEVICES AND SIMPLE CIRCUITS

365566 $n$ -type semiconductor is

1 Negatively charged

2 Positively charged

3 Neutral

4 May be positive or negative