Nature of Electromagnetic Radiation

Q.

What are 3 characteristics of electromagnetic waves?

Q.

Calculate (a) wavenumber and (b) frequency of yellow radiation having wavelength 5800 $\mathring{A}$.

1. $1.724\times {10}^{12}c{m}^{-1}and5.172\times {10}^4{s}^{-1}$

2. $1.724\times {10}^{12}c{m}^{-1}and5.172\times {10}^2{s}^{-1}$

3. $1.724\times {10}^{4}c{m}^{-1}and5.172\times {10}^{12}{s}^{-1}$

4. $1.724\times {10}^{4}c{m}^{-1}and5.172\times {10}^{14}{s}^{-1}$

Q. Newton’s corpuscular theory was able to explain which of the following phenomenon?

1. Interference
2. Polarisation
3. Diffraction
4. Refraction

Q.

Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number ( $\overline{V}$ ) of the yellow light.

Q.

What are the 4 main properties of electromagnetic waves?

Q. The correct sequence of frequency for electromagnetic radiations in the electromagnetic spectrum is:

1. Radio waves > Microwaves > UV rays > X-rays
2. X-rays > UV rays > Microwaves > Radio waves
3. Radio waves > Microwaves > X-rays > UV rays
4. UV rays > X-rays > Radio waves > Microwaves

Q. The shortest wavelength in H spectrum of Lyman series when $R_H=109678c{m}^{-1}$ is

1. 1215.67 Å

2. 1127.30 Å

3. 911.7 Å

4. 1002.7 Å

Q. The frequency of radiation with wavelength 480 nm is:

1. $6.25\times {10}^{14}Hz$
2. $6.25\times {10}^{13}Hz$
3. $6.25\times {10}^{12}Hz$
4. $6.25\times {10}^{11}Hz$

Q.

Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × ${10}^{–10}$ s.

Q.

What is Zeeman effect?

Q.

The ionization energy of hydrogen atom is -13.6 eV. The energy required to excite the electron in a hydrogen atom from the ground state to the first excited state is: (Avogadro's constant =6.022 × 10²³)

1. 1.69 × 10^-20 J

2. 1.69 ×10 ²⁵ J

3. 1.69 × 10^-23 J

4. 1.69 ×10 ²³ J

Q.

A galaxy is moving away from the earth at a speed of $286km/s$. The shift in the wavelength of a redline at $630nm$ is $X\times {10}^{-10}m$. The value of $X$, to the nearest integer, is [Take the value of speed of light, $c=3\times {10}^{8}m{s}^{-1}$]

Q. Photon of which light has maximum energy

1. Red
2. Blue
3. Violet
4. Green

Q. What electronic transition in the $H{e}^{+}$ ion would emit the radiation of the same wavelength as that of the first Lyman transition of hydrogen atom ?

1. $2\to 1$
2. $4\to 2$
3. $3\to 1$
4. $2\to 4$

Q.

A gas absorbs a photon of 355 nm and emits two wavelengths. If one of the emission is at 680 nm, the other is at:

1. 518 nm

2. 743 nm

3. 1035 nm

4. 325 nm

Q.

Arrange the following type of radiations in increasing order of frequency: (a) radiation from microwave oven (b) amber light from traffic signal (c) radiation from FM radio (d) cosmic rays from outer space and (e) X-rays.

Q.

What are some uses for microwave radiation?

Q. A 600 W mercury lamp emits a monochromatic radiation of wavelength 331.3 nm. How many photons are emitted from the lamp per second?
$h=6.626\times {10}^{-34}\text{Js};\text{velocity of light =}3\times {10}^8{\text{ms}}^{-1}$

1. ${10}^{21}$
2. ${10}^{22}$
3. ${10}^{20}$
4. ${10}^{19}$

Q. The ground state energy of hydrogen atom is -13.6 eV. The energy of second excited state of $H{e}^{+}$ ion in eV is

1. -6.04
2. -27.2
3. -54.4
4. -3.4

Q.

An electron and proton possess same K.E., how will their momentum be related?

Q.

The speed of electromagnetic waves in air is

1. $3\times {10}^{5}km/s$

2. $3\times {10}^{6}km/s$

3. $3\times {10}^{7}km/s$

4. $3\times {10}^{8}km/s$

Q. Calculate energy of 2 moles of photons of radiation whose frequency is $5\times {10}^{14}Hz$

1. $3.313\times {10}^{-19}J$
2. $6.626\times {10}^{-19}J$
3. $3990.2kJmo{l}^{-1}$
4. $6790.2kJmol-1$

Q. A certain radio station broadcasts on a frequency of 1890 kHz (kilohertz). What is the wavelength of the electromagnetic radiation broadcasted by the station?

1. 158.7 m
2. 100.5 m
3. 135.9 m
4. 88.2 m

Q.

A 100 Watt bulb emits monochromatic light of wavelength 400 nm. Calculate the number of photons emitted per second by the bulb.

1. 4 $\times$ ${10}^{20}$ $s^{-1}$

2. 2 $\times$ ${10}^{20}$ $s^{-1}$

3. 8 $\times$ ${10}^{20}$ $s^{-1}$

4. 1$\times$ ${10}^{20}$ $s^{-1}$

Q. The certainty in velocity of an electron present in the nucleus of diameter 10 to the power -15 meter hypothetically should be approximately?

Q. Statement - 1: The difference between two adjacent crests is called wavelength.
Statement - 2: Frequency is defined as number of waves that pass a given point in one second.
Statement - 3: The maximum displacement shown by a point on a wave measured from its equivalent position is called wave number.

1. FTT
2. TTF
3. FFT
4. TTT

Q. de Broglie wavelength of charged particles depends on:

1. All above
2. Nature of particle
3. Kinetic energy of particle
4. Mass of particle

Q. Stark effect refers to:

1. "Ejection of photoelectron from a metal surface"
2. "K-electron capture"
3. "Splitting of spectral lines in electric field"
4. Splitting of spectral lines in magnetic field

Q.

Two points on a traveling wave having a frequency $600Hz$ and velocity $300\frac{m}{s}$ are $60°$ out of phase, then the minimum distance between the two points is

1. $0.3$

2. $0.083$

3. $0.25$

4. $0.4$

Q. The angular momentum of the allowed orbits in a $H-$ like species is integral multiple of:

1. $\frac{h}{\pi }$
2. $\frac{h}{2\pi }$
3. $h\pi$
4. $\pi$