Assertion: Magnetic field lines are continuous and closed. 

Reason:  Magnetic monopole does not exist

• 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:  At resonance, LCR series circuit have a minimum current. 

Reason:  At resonance, in LCR series circuit, the current  and  e.m.f are not in phase with each other.

• 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.

In a Fraunhofer diffraction at single slit of width  d  with incident light of wavelength 5500 A^o,  the first minimum is observed, at angle 30°. The first secondary maximum is observed at an angle θ = 

• sin^-1 $\frac{1}{\sqrt{2}}$

• sin^-1$\frac{1}{4}$

• sin^-1$\frac{3}{4}$

• sin^-1$\frac{\sqrt{3}}{2}$

44.

Light wave enters from medium 1 to medium 2. Its velocity in 2^nd medium is double from 1. For total internal reflection the angle of incidence must be greater than

• 30^o

• 60^o

• 45^o

• 90^o

A transparent cube of 15 cm edge contains a small air bubble. Its apparent depth when viewed through one face is 6 cm and when viewed through opposite face is 4 cm. The refractive index of material of cube is

• 2.0

• 1.5

• 1.6

• 2.5

Focal length of objective and eye piece of telescope are 200 cm and 4 cm respectively. What is the length of telescope for normal adjustment?

• 196 cm

• 204 cm

• 250 cm

• 225 cm

The intensity ratio of the maxima and minima in an interference pattern produced by two coherent sources of light is 9 : 1. The intensities of the used light sources are in ratio

• 3 : 1

• 4 : 1

• 9 : 1

• 10 : 1

Which of the following has the longest de Broglie wavelength if they are moving with the same velocity?

• Neutron

• Proton

• $\mathrm{\alpha }$-particle

• β-particle

An atom of mass number 15 and atomic number 7 captures an a-particle and then emits a proton. The mass number and atomic number of the resulting atom will be respectively

• 14 and 12

• 15 and 3

• 16 and 4

• 18 and 8

A zener diode is specified as having a breakdown voltage of 9.1 V, with a maximum power dissipation of 364 mW. What is the maximum current the diode can handle?

• 40 mA

• 60 mA

• 50 mA

• 45 mA