1
MHT CET 2021 21th September Morning Shift
MCQ (Single Correct Answer)
+1
-0

In a pure silicon, number of electrons and holes per unit volume are $$1.6 \times 10^{16} \mathrm{~m}^{-3}$$. If silicon is doped with Boron in a way that on doping hole density increases to $$4 \times 10^{22} \mathrm{~m}^{-3}$$. Then electron density in doped semiconductor will be

A
$$6.4 \times 10^{-9} \mathrm{~m}^{-3}$$
B
$$6.4 \times 10^9 \mathrm{~m}^{-3}$$
C
$$6.4 \times 10^{-10} \mathrm{~m}^{-3}$$
D
$$6.4 \times 10^{10} \mathrm{~m}^{-3}$$
2
MHT CET 2021 21th September Morning Shift
MCQ (Single Correct Answer)
+1
-0

A charge moves with velocity '$$V$$' through electric field $$(E)$$ as well as magnetic field (B). then the force acting on it is

A
$$q(\vec{B} \times \vec{V})$$
B
$$\mathrm{q}(\overrightarrow{\mathrm{V}} \times \overrightarrow{\mathrm{B}})$$
C
$$q \overrightarrow{\mathrm{E}}+q(\vec{V} \times \vec{B})$$
D
$$q(\vec{E} \times \vec{V})$$
3
MHT CET 2021 21th September Morning Shift
MCQ (Single Correct Answer)
+1
-0

Light of frequency two times the threshold frequency is incident on photosensitive material. If the incident frequency is made $$\left(\frac{1}{3}\right)^{\text {rd }}$$ and intensity is doubled, then the photoelectric current will

A
increase
B
decrease
C
be zero
D
be halved
4
MHT CET 2021 21th September Morning Shift
MCQ (Single Correct Answer)
+1
-0

For a transitor, $$\frac{1}{\alpha_{\mathrm{DC}}}-\frac{1}{\beta_{\mathrm{DC}}}$$ is equal to [ $$\alpha_{\mathrm{DC}}$$ and $$\beta_{\mathrm{DC}}$$ are current amplification factors]

A
three
B
two
C
zero
D
one
MHT CET Papers
EXAM MAP