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 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

What feature of the infrared waves make it useful for the haze photography?

A
Since it is invisible
B
Since it has large wave length
C
Since it is absorbed by the medium
D
Since it has high frequency
2
COMEDK 2022
MCQ (Single Correct Answer)
+1
-0

Speed of electromagnetic wave in a medium having relative permittivity $$\varepsilon_r$$ and relative permeability $$\mu_r$$ is (speed of light in air, $$c=3\times10^8$$ m/s)

A
$${1 \over {\sqrt {{\mu _r}{\varepsilon _r}} }}$$
B
$${c \over {\sqrt {{\mu _r}{\varepsilon _r}} }}$$
C
$$c\sqrt {{{{\mu _r}} \over {{\varepsilon _r}}}} $$
D
$${c \over {{\mu _r}{\varepsilon _r}}}$$
3
COMEDK 2022
MCQ (Single Correct Answer)
+1
-0

A 30 mW laser beam has a cross-sectional area of 15 mm2. The magnitude of the maximum electric field in this electromagnetic wave is given by

[Permuittivity of space, $$\varepsilon_0=9\times10^{-12}$$

Speed of light, $$c=3\times10^8$$ m/s]

A
1.22 kV/m
B
12 kV/m
C
10 kV/m
D
201 kV/m
4
COMEDK 2021
MCQ (Single Correct Answer)
+1
-0

The correct arrangement in increasing order of wavelength of X-rays, UV rays, microwave is

A
microwave, X-rays, UV rays
B
UV rays, X-rays, microwave
C
X-rays, UV rays, microwave
D
microwave, UV rays, X-rays
COMEDK Subjects