NEET-UG 2020 · Code E1

For which one of the following, Bohr model is not valid ?

1. AHydrogen atom
2. BSingly ionised helium atom (He+)
3. CDeuteron atom
4. DSingly ionised neon atom (Ne+)

The ratio of contributions made by the electric field and magnetic field components to the intensity of an electromagnetic wave is : (c=speed of electromagnetic waves)

1. Ac:1
2. B1:1
3. C1:c
4. D1 : c2

The Brewsters angle ib for an interface should be :

1. A08 < ib < 308
2. B308 < ib < 458
3. C458 < ib < 908
4. Dib = 908

A cylinder contains hydrogen gas at pressure of 249 kPa and temperature 278C. Its density is : (R=8.3 J mol−1 K−1)

1. A0.5 kg/m3
2. B0.2 kg/m3
3. C0.1 kg/m3
4. D0.02 kg/m3

A ray is incident at an angle of incidence i on one surface of a small angle prism (with angle of prism A) and emerges normally from the opposite surface. If the refractive index of the material of the prism is µ, then the angle of incidence is nearly equal to :

1. AA/2µ
2. B2A/µ
3. CµA
4. DµA/2

Two cylinders A and B of equal capacity are connected to each other via a stop cock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stop cock is suddenly opened. The process is :

1. Aisothermal
2. Badiabatic
3. Cisochoric
4. Disobaric

The energy equivalent of 0.5 g of a substance is :

1. A4.5×1016 J
2. B4.5×1013 J
3. C1.5×1013 J
4. D0.5×1013 J

A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth ?

1. A48 N
2. B32 N
3. C30 N
4. D24 N