Q. No.The number of protons, neutrons and electrons in \( _{71}^{175}Lu\) respectively, are:
1. 104, 71 and 71
2. 71, 71 and 104
3. 175, 104 and 71
4. 71, 104 and 71
| 1. | \(\mathrm {^{56}Fe }\) | 2. | \({ }^{57} \mathrm{Fe}\) |
| 3. | \({ }^{57} \mathrm{Co}\) | 4. | \({ }^{60} \mathrm{Co}\) |
A monochromatic infrared range finder of power 1 milliwatt emits photons with a wavelength of 1000 nm in 0.1 seconds. The number of photons emitted in 0.1 seconds is:
(Given: h = \(6.626 \times 10^{-34} J~s\) , c = \(3 \times 10^8 m~s^{-1}, \) Avogadro number = \(6.022 \times 10^{23}\))
1. \(30 \times 10^{37}\)
2. \(5 \times 10^{14} \)
3. \(30 \times 10^{34} \)
4. \(5 \times 10^{11} \)
A particular station of All India Radio, New Delhi, broadcasts on a frequency of 1,368 kHz (kilohertz). The wavelength of the electromagnetic radiation emitted by the transmitter is: [speed of light, ]
| 1. | 2192 m | 2. | 21.92 cm |
| 3. | 219.3 m | 4. | 219.2 m |
(h = 6.62 × 10–27 ergs, c = 3 × 1010 cm s–1, NA = 6.02 × 1023 mol–1)
| 1. | \({{1.196\times 10^{8}}\over{\lambda}}\) | 2. | \({{2.859\times 10^{5}}\over{\lambda}}\) |
| 3. | \({{2.859\times 10^{16}}\over{\lambda}}\) | 4. | \({{1.196\times 10^{16}}\over{\lambda}}\) |
1. 25
2. 50
3. 75
4. 10
Calculate the energy corresponding to light of wavelength 45 nm:
(Planck's constant h = 6.63 × 10–34 Js & speed of light c = 3 × 108 ms–1)
1. 6.67 x 1015 J
2. 6.67 x 1011 J
3. 4.42 x 10-15 J
4. 4.42 x 10-18 J
(GivenL: h = 6.626 × 10–34 Js, c = 3 × 108 ms–1, NA = 6.022 × 1023 mol–1)
1. 2.31 × 106 J mol–1
2. 3.84 × 104 J mol–1
3. 3.84 × 10–19 J mol–1
4. 2.31 × 105 J mol–1
| 1. | 158.7 Å | 2. | 158.7 pm |
| 3. | 15.87 pm | 4. | 1.587 pm |
Which of the following series of transitions in the spectrum of hydrogen atoms falls in the visible region?
1. Brackett series
2. Lyman series
3. Balmer series
4. Paschen series
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