Assertion: The magnetic poles of earth do not coincide with the geographic poles. 

Reason:  The discrepancy between the orientation of a compass and true north-south direction is known as magnetic declination.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion:  Electromagnetic waves are transverse in nature 

Reason: The electric and magnetic fields of an e.m. wave are perpendicular to each other and also perpendicular to the direction of wave propogation.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion:  If  a proton and an a-particle enter a uniform magnetic field perpendicularly with the same speed, the time period of revolution of a particle is double that of proton. 

Reason:  In a magnetic field, the period of revolution of a charged particle is directly proportional to the mass of the particle and is inversely proportional to charge of particle.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Assertion:  It is advantageous to transmit electric power at high voltage.

Reason: High voltage implies high current.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Assertion:  X-ray astronomy is possible only from satellites orbiting the earth. 

Reason:  Efficiency of X-rays telescope is large as compared to any other telescope.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false

Transmission lines transmit a voltage of V volt to our houses from power stations, then the power P supplied by them is proportional to

• $\frac{1}{\mathrm{V}}$

• V

• V²

• $\frac{1}{{\mathrm{V}}^2}$

47.

The logic gate represented in the following figure is 

• OR gate

• NOT gate

• NAND gate

• XOR gate

For a person near point of vision is  100 cm. Then the power of lens he must wear so as to have normal vision, should be

• + 1D

• $- 1$D

• + 3D

• $- 3$D

What would be maximum wavelength for Brackett series of hydrogen-spectrum?

• 74589 A^o

• 22790 A^o

• 40519 A^o

• 18753 A^o

What would be the radius of second orbit of  He⁺  ion?

• 1.508 A^o

• 3.023 A^o

• 2.068 A^o

• 4.458 A^o