Semiconductor Electronics: Materials, Devices and Simple Circuits — Physics STD 12 Science — Question

Assertion  : The positively charged nucleus of an atom has a radius of almost .

Reason      : In a-particle scattering experiment, the distance of closest approach for a-particles is

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

The basic magnetization curve for a ferromagnetic material is shown in figure. Then, the value of relative permeability is highest for the point

(a) P

(b) Q

(c) R

(d) S

Capacitiors are used in electrical circuits where appliances need more:

What is the average binding energy per nucleon over a wide range?

In the circuit shown here, E₁ = E₂ = E₃ = 2 V and R₁ = R₂ = 4 ohms.  The current flowing between points A and B through battery E₂ is

(a) Zero	(b) 2 amp from A to B
(c) 2 amp from B to A	(d) None of the above

According to classical theory, the circular path of an electron in Rutherford atom is

(a) Spiral

(b) Circular

(c) Parabolic

(d) Straight line

Assertion  :   The lightening conductor at the top of high building has sharp pointed ends.

Reason     : The surface density of charge at sharp points is very high resulting in setting up of electric wind.

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

An important spectral emission line has a wavelength of 21 cm. The corresponding photon energy is  (h = 6.62

(a) 5.9

(b) 5.9

(c) 5.9

(d) 11.8

The work function of a metal is:

The energy band gap is maximum in: