KVPY Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics: Questions 235 - 237 of 268

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 268 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 200.00 or

Question number: 235

» Dual Nature of Matter and Radiation » Photoelectric Effect

Appeared in Year: 2014

MCQ▾

Question

A 160 watt light source is radiating light of wavelength 6200 Å uniformly in all directions. The photon flux at a distance of 1.8 m is of the order of (Planck’s constant 6.63 × 10–34 J-s)

Choices

Choice (4) Response

a.

Equation

b.

Equation

c.

Equation

d.

Equation

Question number: 236

» Atoms and Nuclei » Radioactivity

Appeared in Year: 2015

MCQ▾

Question

Carbon -11 decays to boron -11 according to the following formula.

Equation

Assume that positrons (e+) produced in the decay combine with free electron in the atmosphere and annihilate each other almost immediately. Also assume that the neutrinos (νe) are massless and do not interact with the environment. At t = 0 we have 1 µg of Equation . If the half-life of the decay process is t0, the net energy produced between time t = 0 and t = 2t0 will be nearly,

Choices

Choice (4) Response

a.

Equation

b.

Equation

c.

Equation

d.

Equation

Question number: 237

» Atoms and Nuclei » Energy Levels

Appeared in Year: 2014

MCQ▾

Question

The wavelength of the first Balmer line caused by a transition from the n = 3 level to the n = 2 level in hydrogen is λ1. The wavelength of the line caused by an electronic transition from n = 5 to n = 3 is –

Choices

Choice (4) Response

a.

Equation

b.

Equation

c.

Equation

d.

Equation

f Page
Sign In