JEE Main 2019 (Online) 9th April Evening Slot | Heat and Thermodynamics Question 219 | Physics

JEE Main 2019 (Online) 9th April Evening Slot

MCQ (Single Correct Answer)

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50 W/m² energy density of sunlight is normally incident on the surface of a solar panel. Some part of incident energy (25%) is reflected from the surface and the rest is absorbed. The force exerted on 1m² surface area will be close to (c = 3 × 108 m/s) :-

20 × 10^–8 N

35 × 10^–8 N

10 × 10–8 N

15 × 10^–8 N

JEE Main 2019 (Online) 9th April Evening Slot

MCQ (Single Correct Answer)

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The specific heats, C_P and C_V of a gas of diatomic molecules, A, are given (in units of J mol^–1 K^–1) by 29 and 22, respectively. Another gas of diatomic molecules, B, has the corresponding values 30 and 21. If they are treated as ideal gases, then :-

A is rigid but B has a vibrational mode

A has a vibrational mode but B has none

A has one vibrational mode and B has two

Both A and B have a vibrational mode each

JEE Main 2019 (Online) 9th April Morning Slot

MCQ (Single Correct Answer)

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An HCl molecule has rotational, translational and vibrational motions. If the rms velocity of HCl molecules in its gaseous phase is $$\overline v $$ , m is its mass and k_B is Boltzmann constant, then its temperature will be :

$${{m{{\overline v }^2}} \over {5{k_B}}}$$

$${{m{{\overline v }^2}} \over {6{k_B}}}$$

$${{m{{\overline v }^2}} \over {7{k_B}}}$$

$${{m{{\overline v }^2}} \over {3{k_B}}}$$

JEE Main 2019 (Online) 9th April Morning Slot

MCQ (Single Correct Answer)

-1

Following figure shows two processes A and B for a gas. If $$\Delta $$Q_A and $$\Delta $$Q_B are the amount of heat absorbed by the system in two cases, and $$\Delta $$U_A and $$\Delta $$U_B are changes in internal energies, respectively, then : JEE Main 2019 (Online) 9th April Morning Slot Physics - Heat and Thermodynamics Question 222 English