Electromagnetism
Current Electricity
MCQ (Single Correct Answer)
Moving Charges and Magnetism
MCQ (Single Correct Answer)
Magnetism and Matter
MCQ (Single Correct Answer)
Electromagnetic Induction
MCQ (Single Correct Answer)
Alternating Current
MCQ (Single Correct Answer)
Electromagnetic Waves
MCQ (Single Correct Answer)
Modern Physics
Dual Nature of Radiation
MCQ (Single Correct Answer)
Semiconductor Devices and Logic Gates
MCQ (Single Correct Answer)
Communication Systems
MCQ (Single Correct Answer)
1
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { In a p-n junction, the depletion layer of thickness } 1 \mu \mathrm{m} \text { has } 0.05 \mathrm{~V} \text { potential across it. The electric field in } N C^{-1} \text { is } $$

A
$$ 5 \times 10^{-8} $$
B
$$ 5 \times 10^{2} $$
C
$$ 5 \times 10^{5} $$
D
$$ 5 \times 10^{4} $$
2
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

The mobility of the charge carriers increases with

A
The average collision time
B
Increase in the mass of the charge
C
Increase in the electric field
D
Decrease in the charge of the mobile carriers
3
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

In intrinsic semiconductors at room temperature, number of electrons and holes are

A
zero
B
infinity
C
unequal
D
equal
4
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

A semiconductor $$\mathrm{X}$$ is made by doping silicon with phosphorous. A second semiconductor $$\mathrm{Y}$$ is made by doping silicon with aluminium. The two are joined by a suitable technique to form a $$\mathrm{p}$$-$$\mathrm{n}$$ junction and is connected to a battery such that $$\mathrm{Y}$$ is joined to negative of the battery and $$\mathrm{X}$$ to the positive of the battery. Which of the following statements is correct?

A
Potential barrier of the junction is zero and current is due to minority carriers
B
Potential barrier of the junction is raised and current is due to majority carriers
C
Potential barrier of the junction is raised and current is due to minority carriers
D
Potential barrier of the junction is lowered and current is due to minority carriers
COMEDK Subjects