The total electric flux for the following closed surface which is kept inside water

(a)

\(\frac { 80q }{ { \varepsilon }_{ 0 } } \)

(b)

\(\frac { q }{ { 40\varepsilon }_{ 0 } } \)

(c)

\(\frac { q }{ { 80\varepsilon }_{ 0 } } \)

(d)

\(\frac { q }{ { 160\varepsilon }_{ 0 } } \)

The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?

(a)

2 ohm

(b)

4 ohm

(c)

8 ohm

(d)

1 ohm

A thin insulated wire forms a plane spiral of N = 100 tight turns carrying a current I = 8 m A (milli ampere). The radii of inside and outside turns are a = 50 mm and b = 100 mm respectively. The magnetic induction at the centre of the spiral is ______.

(a)

\(5\mu T\)

(b)

\(7\mu T\)

(c)

\(8\mu T\)

(d)

\(10\mu T\)

The flux linked with a coil at any instant t is given by \(\Phi\)_B = 10t² − 50t + 250. The induced emf at t = 3s is

(a)

−190 V

(b)

−10 V

(c)

10 V

(d)

190 V

Consider an oscillator which has a charged particle oscillating about its mean position with a frequency of 300 MHz. The wavelength of electromagnetic waves produced by this oscillator is _____.

(a)

1 m

(b)

10 m

(c)

100 m

(d)

1000 m

Stars twinkle due to, ______.

(a)

reflection

(b)

total internal reflection

(c)

refraction

(d)

polarisation

A photoelectric surface is illuminated successively by monochromatic light of wavelength λ and λ /2. If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the material is _____.

(a)

\(\frac{hc}{\lambda}\)

(b)

\(\frac{2hc}{\lambda}\)

(c)

\(\frac{hc}{3\lambda}\)

(d)

\(\frac{hc}{2\lambda}\)

The charge of cathode rays particle is _____.

(a)

Positive

(b)

negative

(c)

neutral

(d)

not defined

If the nuclear radius of ²⁷Al is 3.6 fermi, the approximate nuclear radius of ⁶⁴Cu, in femi is _____.

(a)

2:4

(b)

1.2

(c)

4.8

(d)

3.6

Which one of the following is the natural nanomaterial.

(a)

Peacock feather

(b)

Peacock beak

(c)

Grain of sand

(d)

Skin of the Whale