Orbital having 3 angular nodes and 3 total nodes is:

1. 5 p 2. 3 d
3. 4 f 4. 6 d
Subtopic:  Nodal Plane |
 79%
Level 2: 60%+
NEET - 2019
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In hydrogen atom, what is the de Broglie wavelength of an electron in the second Bohr orbit is: [Given that Bohr radius, a0=52.9 pm]

1. 211.6 pm

2. 211.6 πpm

3. 52.9 πpm

4. 105.8 pm

Subtopic:  Bohr's Theory |
Level 3: 35%-60%
NEET - 2019
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The volume occupied by 1.8 g of water vapour at 374 oC and 1 bar pressure will be -

[Use R=0.083 bar LK-1 mol-1]

1. 96.66 L

2. 55.87 L

3. 3.10 L

4. 5.31 L

Subtopic:  Ideal Gas Law |
 73%
Level 2: 60%+
NEET - 2019
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What is the amount of work done by an ideal gas, if the gas expands isothermally from \(10^{-3}~m^3\) to \(10^{-2}~m^3\) at \(300~K\)against a constant pressure of \(10^{5}~Nm^{-2}\)?

1. \(+270 ~kJ\) 2. \(–900 ~J\)
3. \(+900 ~kJ\) 4. \(–900~ kJ\)
Subtopic:  First Law of Thermodynamics |
 72%
Level 2: 60%+
NEET - 2019
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Reversible expansion of an ideal gas under isothermal and adiabatic conditions are shown in the figure:

AB→Isothermal expansion

AC→Adiabatic expansion

Which of the following options is not correct?

1. \(\Delta S_{\text {isothermal }}>\Delta S_{\text {adiabatic }} \) 2. \(T_A=T_B \)
3. \(W_{\text {isothermal }}>W_{\text {adiabatic }} \) 4. \(T_C>T_A\)
Subtopic:  2nd & 3rd Law of Thermodynamics |
 55%
Level 3: 35%-60%
NEET - 2019
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Two metal spheres, one of radius \(R\) and the other of radius \(2R\) respectively have the same surface charge density \(\sigma.\) They are brought in contact and separated.  What will be the new surface charge densities on them?
1. \(\sigma_{1}=\dfrac{5}{6}\sigma ,~\sigma_{2}=\dfrac{5}{6}\sigma\)
2. \(\sigma_{1}=\dfrac{5}{2}\sigma ,~\sigma_{2}=\dfrac{5}{6}\sigma\)
3. \(\sigma_{1}=\dfrac{5}{2}\sigma ,~\sigma_{2}=\dfrac{5}{3}\sigma\)
4. \(\sigma_{1}=\dfrac{5}{3}\sigma ,~\sigma_{2}=\dfrac{5}{6}\sigma\)
Subtopic:  Electric Potential |
 58%
Level 3: 35%-60%
NEET - 2019
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The distance covered by a particle undergoing SHM in one time period is: (amplitude \(= A\))
1. zero
2. \(A\)
3. \(2 A\)
4. \(4 A\)

Subtopic:  Simple Harmonic Motion |
 77%
Level 2: 60%+
NEET - 2019
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A mass falls from a height \(h\) and its time of fall \(t\) is recorded in terms of time period \(T\) of a simple pendulum. On the surface of the earth, it is found that \(t=2T\). The entire setup is taken on the surface of another planet whose mass is half of that of the Earth and whose radius is the same. The same experiment is repeated and corresponding times are noted as \(t'\) and \(T'\). Then we can say:

1. \(t' = \sqrt{2}T\) 2. \(t'>2T'\)
3. \(t'<2T'\) 4. \(t' = 2T'\)
Subtopic:  Acceleration due to Gravity |
Level 3: 35%-60%
NEET - 2019
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A tuning fork with a frequency of \(800\) Hz produces resonance in a resonance column tube with the upper end open and the lower end closed by the water surface. Successive resonances are observed at lengths of \(9.75\) cm, \(31.25\) cm, and \(52.75\) cm. The speed of the sound in the air is:
1. \(500\) m/s 2. \(156\) m/s
3. \(344\) m/s 4. \(172\) m/s
Subtopic:  Speed of Sound |
 74%
Level 2: 60%+
NEET - 2019
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An object flying in the air with velocity \((20 \hat{i}+25 \hat{j}-12 \hat{k})\) suddenly breaks into two pieces whose masses are in the ratio of \(1:5.\) The smaller mass flies off with a velocity \((100 \hat{i}+35 \hat{j}+8 \hat{k})\). The velocity of the larger piece will be:
1. \( 4 \hat{i}+23 \hat{j}-16 \hat{k}\)
2. \( -100 \hat{i}-35 \hat{j}-8 \hat{k} \)
3. \( 20 \hat{i}+15 \hat{j}-80 \hat{k} \)
4. \( -20 \hat{i}-15 \hat{j}-80 \hat{k}\)

Subtopic:  Collisions |
 75%
Level 2: 60%+
NEET - 2019
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