# Physics

Quiz by , created over 1 year ago

## Quiz on Physics, created by raghu Katagall on 09/11/2017.

1774
0
0
No tags specified
 Created by raghu Katagall over 1 year ago
Memory-boosting tips for students
SFDC App Builder Quizlet
World War I
Salesforce Admin 201 Exam Chunk 1 (1-30)
Část 6.
Maths C4 Trig formulae (OCR MEI)
FREQUENCY TABLES: MODE, MEDIAN AND MEAN
IB Chem Flashcards
Anatomy and Physiology - BIO 111 - Test #1 Flashcards
Historia matematyki II

### Question 1

Question
In the Bohr model of the hydrogen atom, let R, V and E represent the radius of the orbit, the speed of electron and the total energy of the electron respectively. Which of the following quantity is proportional to the quantum number n?
• VR
• RE
• E/V
• R/E

### Question 2

Question
The work function for aluminium is 4.125 eV. The cut off wavelength for photoelectric effect for Aluminium is
• 200 nm
• 300 nm
• 150 nm
• 420 nm

### Question 3

Question
The electron is a hydrogen atom makes a transition from n = n1 to n = n2 state. The time period of the electron in the final state is eight times that in the initia state. Then the possible values of n1 and n2 are
• n1 = 8, n2 = 2
• n1 = 4, n2 = 2
• n1 = 6, n2 = 2
• n1 = 1, n2 = 2

### Question 4

Question
Light of frequency 1.5 times the threshold frequency is incident on photosensitive material. If the frequency is halved and intensity is doubled, the photocurrent becomes
• Doubled
• Zero
• Halved

### Question 5

Question
A radioactive substance has a half life of four months. Three fourth of the substance will decay in
• 12 months
• 4 months
• 8 months
• 3 months

### Question 6

Question
A radio isotope has a half life of 5 years. The fraction of the atoms of this material that would decay in 15 years will be
• 1
• 2/3
• 7/8
• 5/8

### Question 7

Question
When Boron 5B10 is bombarded by neutron,  particles are emitted. The resulting nucleus has mass number
• 11
• 6
• 7
• 15

### Question 8

Question
Tracer techniques make use of
• neutron scattering
• electron beams
• lasers

### Question 9

Question
A sample of radioactive substance contains 2,828 atoms. If its half life is two days, how many atoms will be left intact in the sample after one day?
• 2,000
• 1,000
• 1,414
• 707

### Question 10

Question
The unit of Planck’s constant is
• Nm
• eV
• Js–1
• Js

### Question 11

Question
Mean life of a radioactive element is one year. Then its half life is (years)
• 0.5
• 0.4
• 1
• 0.693

### Question 12

Question
Hydrogen atom emits blue light when it jumps from n = 4 energy level to the n = 2 energy level. Which colour of light would the atom emit when it jumps from the n = 5 level to the n = 2 level?
• Red
• Yellow
• Green
• Violet

### Question 13

Question
The electromagnetic theory of light was developed by
• Max Planck
• Maxwall
• Newton
• Huygens

### Question 14

Question
The concept of quantum nature of light has emerged in an attempt to explain
• photoelectric effect
• polarisation of light
• interference and diffraction.

### Question 15

Question
The electron in the innermost orbit of an atom has _____ velocity.
• mean
• zero
• highest
• lowest

### Question 16

Question
Einstein’s photoelectric equation was experimentally verified by
• Millikan
• Rutherford
• Einstein
• Fermi
• all the above

### Question 17

Question
A photon of energy 8 eV is incident on a metal surface of threshold frequency 1.6  1015 Hz. The K.E of the photoelectrons emitted (in eV) (Take h = 6  10–34 Js)
• 2
• 1.2
• 1.6
• 6

### Question 18

Question
TV waves have a wavelength range of 1-10 metre. This frequency range in MHz is
• 3 – 3000
• 300 – 3000
• 3 – 30
• 30 – 300

### Question 19

Question
. An electron and a proton have the same de-Broglie wavelength. Then the kinetic energy of the electron is
• greater than the kinetic energy of the proton
• zero
• Infinity
• equal to the kinetic energy of the proton

### Question 20

Question
Whenever a hydrogen atom emits a photon in the Balmer series
• It may emit another photon in the Balmer series
• It must emit another photon in the Lyman series
• It may emit another photon in the Paschen series
• It need not emit any more photon

### Question 21

Question
The de Broglie wavelength of an electron in the first Bohr orbit is