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. \(5 \times 10^{11} \)
The correct order of spin-only magnetic moment for the given complexes is:
1. \([Co(H_2O)_6]^{2+} > [MnCl_6]^{3-} > [Fe(CN)_6]^{3-} \)
2. \([Fe(CN)_6]^{3-} >[Co(H_2O)_6]^{2+} > [MnCl_6]^{3-} \)
3. \([MnCl_6]^{3-} >[Fe(CN)_6]^{3-} >[Co(H_2O)_6]^{2+} \)
4. \([MnCl_6]^{3-} > [Co(H_2O_6]^{2+} > [Fe(CN)_6]^{3-} \)
A student collected samples from two water bodies A and B in a metro city. The biochemical oxygen demand for 'A' is 3 ppm while for B is found to be 18 ppm. Which one of the following is true?
1. Both A and B are clean
2. Both A and B are polluted
3. A is clean but B is polluted
4. A is polluted but B is clean
Identify the pair of Lanthanoides with one strong oxidant and one strong reductant:
| 1. | Ce(IV), Tb(IV) | 2. | Yb(II), Eu(II) |
| 3. | Eu(IV), Lu(III) | 4. | Ce(IV), Eu(II) |
Find the compound formed when water is added to an alkyne containing more than two carbon atoms in the presence of HgSO₄ and dilute H₂SO₄ at 333 K.
1. A vicinal diol
2. An aldehyde
3. An alcohol
4. A ketone
Given below are two statements:
| I: | The Ellingham diagram provides an idea about the feasibility of a reaction. |
| II: | The Ellingham diagram explains the rate of the reduction reactions. |
In light of the above statements, choose the most appropriate answer from the options given below:
| 1. | I is correct and II is incorrect. |
| 2. | I is incorrect and II is correct. |
| 3. | Both I and II are correct. |
| 4. | Both I and II are incorrect. |
At 300 K, 250 mL of gas A at 1 bar pressure is mixed with 500 mL of a gas B at 2 Bar pressure in a 1.0 L flask. Gas A does not react with gas B. The final pressure of the mixture is-
1. 1.00 bar
2. 2.15 bar
3. 2.50 bar
4. 1.25 bar
Which statements among the following is not correct?
| 1. | When conduction band and valence band overlap, a semiconductor is obtained |
| 2. | Ferrimagnetism arises due to the alignment of magnetic moments of the domains in the substance in parallel and anti-parallel directions in unequal numbers |
| 3. | Replacing some silicon atoms by boron atoms in crystal of silicon produces p-type semiconductor |
| 4. | Replacing some germanium atoms by phosphorus atoms in a crystal of germanium produces n-type semiconductor |
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