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 Morning Shift
MCQ (Single Correct Answer)
+1
-0

In a given semiconductor, the ratio of the number density of electron to number density of hole is $$2: 1$$. If $$\frac{1}{7}$$th of the total current is due to the hole and the remaining is due to the electrons, the ratio of the drift velocity of holes to the drift velocity of electrons is :

A
$$\frac{2}{3}$$
B
$$\frac{3}{1}$$
C
$$\frac{3}{2}$$
D
$$\frac{1}{3}$$
2
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

An ideal diode is connected in series with a capacitor. The free ends of the capacitor and the diode are connected across a $$220 \mathrm{~V}$$ ac source. Now the potential difference across the capacitor is :

A
$$110 \mathrm{~V}$$
B
$$311 \mathrm{~V}$$
C
$$2 \sqrt{110} \mathrm{~V}$$
D
$$\sqrt{220} \mathrm{~V}$$
3
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

Though $$\mathrm{Sn}$$ and $$\mathrm{Si}$$ are $$4^{\text {th }}$$ group elements, $$\mathrm{Sn}$$ is a metal while $$\mathrm{Si}$$ is a semiconductor because

A
$$\mathrm{Sn}$$ has more electrons than $$\mathrm{Si}$$
B
The energy gap of $$\mathrm{Sn}$$ is zero volt while that of $$\mathrm{Si}$$ is $$0.07 \mathrm{~V}$$
C
The energy gap of $$\mathrm{Sn}$$ is $$1.1 \mathrm{~eV}$$ volt while that of $$\mathrm{Si}$$ is $$0.07 \mathrm{~V}$$
D
$$\mathrm{Sn}$$ has more holes than $$\mathrm{Si}$$
4
COMEDK 2023 Morning Shift
MCQ (Single Correct Answer)
+1
-0

A transistor is connected in CE configuration. The collector supply is $$10 \mathrm{~V}$$ and the voltage drop across a resistor of $$1000 \Omega$$ in the collector circuit is $$0.5 \mathrm{~V}$$. If the current gain factor is 0.96 , then the base current is

A
$$25_6 \mu \mathrm{A}$$
B
$$20.8 \mu \mathrm{A}$$
C
$$22.5 \mu \mathrm{A}$$
D
$$15 \mu \mathrm{A}$$
COMEDK Subjects