An uncharged metal sphere is placed between two equal and oppositely charged metal plates. The nature of lines of force will be ______________

(a)

(b)

(c)

(d)

In three-phase AC generator the three coils are fastened rigidly together and are displaced from each other by an angle _______________.

(a)

90°

(b)

180°

(c)

120°

(d)

360°

In an a.c. circuit with an inductor ______________.

(a)

voltage lags current by π/2

(b)

voltage and current are in phase

(c)

voltage leads current by π

(d)

current lags voltage by π/2

In an LCR series a.c, circuit, the phase difference between current and voltage is 60°. If the net reactance of the circuit is 17.32Ω, the value of the resistance is ______________.

(a)

30Ω

(b)

17.32 Ω

(c)

10 Ω

(d)

1.732 Ω

Which of the following is used to study crystal structure?

(a)

microwave

(b)

infrared rays

(c)

ultraviolet rays

(d)

X-rays

Electromagnetic waves are _________ in nature.

(a)

parallel

(b)

transverse

(c)

longitudinal

(d)

Uni-directional

________ radiations are used to study atomic structure.

(a)

UV

(b)

IR

(c)

X-rays

(d)

Gamma

The speed of light in an isotropic medium depends on, ______.

(a)

its intensity

(b)

its wavelength

(c)

the nature of propagation

(d)

the motion of the source w.r.t medium

If γ is the frequency of characteristic X-ray line emitted by a target element of atomic number Z, then Moseley's law is __________________.

(a)

γ α Z

(b)

γ α \(\sqrt Z\)

(c)

γ α Z²

(d)

γ α Z³

The orbits in which electrons supposed to be revolving according to Rutherford are ___________

(a)

square-shaped

(b)

circular

(c)

rectangular

(d)

linear

__________ Scanning Electron Micrograph (SEM) showing the nano structures on the surface of a leaf from a lotus plant

(a)

Parrot fish

(b)

Morpho butterfly

(c)

Lotus leaf surface

(d)

Peacock feathers

From the follwoing semi-conductor devices _________ operates in forward bias only.

(a)

varactar diode

(b)

zener diode

(c)

light emitting diode

(d)

photo-diode

Noise is a form of __________ variation.

(a)

time

(b)

phase

(c)

amplitude

(d)

frequency

Atomic number of SI is ______

(a)

14

(b)

12

(c)

16

(d)

18

In a junction transistor the emitter region is heavily doped since emitter has to supply to the base Zener diode acts as a __________

(a)

minority carrier

(b)

majority carrier

(c)

acceptor ions

(d)

donor ions

(i) How is the speed of Electromagnetic waves in vacuum determined by the electric and magnetic fields? and
(ii) Do Electromagnetic waves carry energy and momentum?

When a wave undergoes reflection at a denser medium, what happens to its phase?

Give the results of Rutherford alpha scattering experiment.

Define atomic mass unit u.

What are sub atomic particles?

What kind of blueprint does the natural structure provide?

Calculate the electric dipole moment for the following charge configurations.

How are the three different emfs generated in a three-phase AC generator? Show the graphical representation of these three emfs.

What is the phase relation between current and emf in an AC circuit containing a cpacitor only? Sketch a graph showing the variation the reactance of a capacitor with frequency.

Digine atomic mass unit. Find its energy equivalent in MeV

Write the application of nano robots in medical field?

Give the Schematic representation of valence band, conduction band, and forbidden energy gap and draw energy band structure of
(a) Insulators
(b) Semiconductors
(c) Metals?

Compute the speed of the electromagnetic wave in a medium if the amplitude of electric and magnetic fields are 3 x 10⁴ N C^–1 and 2 x 10^–4 T, respectively.

The oscillating magnetic field in a plane Electromagnetic wave is given by
B = (8 x 10^-6) sin (2 x 10¹¹ t + 300 πx) T
(i) Calculate the λ of Electromagnetic wave.
(ii) Find the amplitude of electric field.

Explain the results of Rutherford α-particle scattering experiment.

Two stable isotopes of lithium \(_{ 3 }^{ 6 }{ Li }\) and \(_{ 3 }^{ 7 }{ Li }\) have respective abundances of 7.5% and 92.5%. These isotopes have masses 6.01512 u and 7.01600 u respectively. Find the atomic mass of lithium.

Write the advantages and disadvantages of robotic.