JEE Main Question Paper 2019 (Available): Check Previous Year Question Paper with Solution PDF (2024-2014)

1.

The magnetic field in a plane electromagnetic wave is \[ B_y = (3.5 \times 10^{-7}) \sin \left( 1.5 \times 10^3 x + 0.5 \times 10^{11} t \right) \, \text{T}. \] The corresponding electric field will be:

• \( E_y = 1.17 \sin \left( 1.5 \times 10^3 x + 0.5 \times 10^{11} t \right) \, \text{V/m} \)
• \( E_z = 105 \sin \left( 1.5 \times 10^3 x + 0.5 \times 10^{11} t \right) \, \text{V/m} \)
• \( E_z = 1.17 \sin \left( 1.5 \times 10^3 x + 0.5 \times 10^{11} t \right) \, \text{V/m} \)
• \( E_y = 10.5 \sin \left( 1.5 \times 10^3 x + 0.5 \times 10^{11} t \right) \, \text{V/m} \)

2.

A hydrogen atom in ground state is given an energy of 10.2 eV. How many spectral lines will be emitted due to transition of electrons ?

• 6
• 3
• 10
• 1

3.

In the above reaction product ’P’ is

4.

The temperature of a gas is \(-78^\circ\text{C}\) and the average translational kinetic energy of its molecules is \( K \). The temperature at which the average translational kinetic energy of the molecules of the same gas becomes \( 2K \) is:

• \(-39^\circ\text{C}\)
• \(117^\circ\text{C}\)
• \(127^\circ\text{C}\)
• \(-78^\circ\text{C}\)

5.

The following figure represents two biconvex lenses \( L_1 \) and \( L_2 \) having focal lengths 10 cm and 15 cm, respectively. The distance between \( L_1 \) and \( L_2 \) is:

• 10 cm
• 15 cm
• 25 cm
• 35 cm