CSIR Physical Sciences: Questions 321 - 323 of 401

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 401 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 300.00 or

Question number: 321

» Thermodynamic and Statistical Physics » Free Energy

Appeared in Year: 2012

MCQ▾

Question

The free energy difference between the superconducting and the normal states of a material is given by, ΔF=FSFN=α ψ 2+β2 ψ 4 where ψ is an order parameter and α and β are constants such that α>0 in the normal and α<0 in the superconducting state, while β>0 always. The minimum value of ΔF is – (December)

Choices

Choice (4) Response

a.

3α22β

b.

α22β

c.

5α22β

d.

α2β

Question number: 322

» Quantum Mechanics » Timeindependent Perturbation Theory and Applications

Appeared in Year: 2011

MCQ▾

Question

A constant perturbation as shown in the figure below acts on a particle of mass m confined in an infinite potential well between 0 and L.

A constant perturbation is given

A Constant Perturbation Is Given

Above figure gives a constant perturbation acts on a particle confined in an infinite potential well between 0 and L.

The first – order correction to the ground state energy of the particle is –

Choices

Choice (4) Response

a.

V02

b.

V04

c.

3V02

d.

3V04

Passage

Light of wavelength 660 nm and power of 1mW is incident on a semiconductor photodiode with an absorbing layer of thickness of ln4μm .

Question number: 323 (1 of 2 Based on Passage) Show Passage

» Electronics and Experimental Methods » Opto-Electronic Devices » Photo-Detectors

MCQ▾

Question

The generated photo – current for a quantum efficiency of unity will be –

Choices

Choice (4) Response

a.

360μA

b.

400μA

c.

120μA

d.

133μA

f Page
Sign In