JEE 2020 : Weekly Quiz 31 (28.09.2019) for JEE & BITSAT Exams

Question 1

If the stationary proton and a - particle are accelerated through same potential difference, the ratio of de-Broglie wavelength will be

Question 2

The wavelength of K_a X-rays produced by an X-ray tube is 0.76 Å. The atomic number of anticathode materials is

Question 3

When a metallic surface is illuminated with monochromatic light of wavelength λ the stopping potential for photoelectric current is 3 V_o. When the same metallic surface is illuminated with a light of wavelength 2λ, the stopping potential is V₀. The threshold wavelength for the surface is

Question 4

The ratio of de-Broglie wavelength of molecules of hydrogen and helium in two gas jars kept separately at temperature 27°C and 127⁰C respectively is

Question 5

Light of wavelength of 2000Å falls on an aluminium surface. In aluminium 4.2 eV are required to remove an electron from its surface. [Planck’s constant h = 6.6 × 10^-34 joule –second , and speed of light c = 3 × 10⁸ m/s].

What is the stopping potential?

Question 6

The electron of a hydrogen atom makes a transition from the (n+1)^th orbit to the n^th orbit. For large n the wavelength of the emitted radiation is proportional to

Question 7

The ratio of de-Broglie wavelength of molecules of hydrogen and helium which are at temperature 27^oC and 127^oC respectively is

Question 8

After absorbing a slowly moving neutron of mass m_N (momentum almost zero) a nucleus of mass M breakes into two nuclei of masses m₁ and 5m₁ (6m₁ = M + m_N) respectively. If the De-Broglie wavelength of the nucleus with mass m₁ is λ, then De-Broglie wavelength of the other nucleus will be

Question 9

The de-Broglie wavelength (λ_B) associated with the electron orbiting in the second excited state of hydrogen atom is related to that in the ground state (λ_G) by :

Question 10

Two electrons are moving with non-relativistic speeds perpendicular to each other. If corresponding de Broglie wavelengths are λ₁ and λ₂, their de Broglie wavelength in the frame of reference attached to their centre of mass is :

Question 11

Which one of the following events takes place after double fertilisation?

Question 12

On strong heating silver nitrate which gas will produce

Question 13

Which carbonate on heating produce two type of gas?

Question 14

Which Nitrate on heating left no residue?

Question 15

Which Nitrate on normal heating produce only one type of gas?

Question 16

If an electron has magnetic quantum number -2, the value of principal quantum number is

Question 17

The value of l for the dumb-bell shaped orbital is

Question 18

Which rule is violated if the electron structure of oxygen atom is written as 1s⁰ 2s² 2p⁴?

Question 19

The plot of log k versus 1/T is linear with a slope of

Question 20

Thermal decomposition of a compound is of first order. If 50% of a sample of the compound is decomposed in 120 minutes. How long will it take for 90% of the compound to decompose?

Question 21

The number of diagonals in a regular polygon of 100 sides is

Question 22

The letters of the word COCHIN are permuted and all permutations are arranged in an alphabetical order as in English dictionary. The number of words that appear before the word COCHIN is

Question 23

The number of permutations by taking all letters and keeping the vowels of the word COMBINE in the odd places is

Question 24

All possible two-factor products are formed from the numbers 1, 2, ------100. The number of factors out of the total obtained which are multiple of 3 is-

Question 25

The number of ways selecting 8 books from a library which has 10 books each of Mathematics, Physics, Chemistry and English, if books of the same subject are alike, is-

Question 26

There are 12 balls numbered from 1 to 12. The number of ways in which they can be used to fill 8 places in a row so that the balls are with numbers in ascending or descending order is equal to-

Question 27

The number of different seven digit numbers that can be written using only the three digits 1, 2 and 3 with the condition that the digit 2 occurs twice in each number is-

Question 28

Two events A and B will be independent if

Question 29

Let us consider 2 events namely A and B, they will be independent if

Question 30

A dice is thrown 3 times. Each time one number is eliminated by putting a silver paper on that side. What is the probability that 3 is left after 2 times of such trail?