Positive Rays and Neutrons

Q. The de-broglie wavelength of an electron accelerated by an electric potential of 'V' volts is given by
$(Given:m_e=9.1\times {10}^{-31}kg,e=1.6\times {10}^{-19}C,h=6.6\times {10}^{-34}J/s)$

1. $\lambda =\frac{1.23}{\sqrt{m}}m$
2. $\lambda =\frac{1.23}{\sqrt{h}}m$
3. $\lambda =\frac{1.23}{\sqrt{V}}nm$
4. $\lambda =\frac{1.23}{V}nm$

Q. The relative charge on an electron, proton and a neutron are:

1. +1, +1, 0
2. -1, +1, 0
3. -1, 0, +1
4. 0, +1, -1

Q.

Which subatomic particle is present in the nucleus of an atom?

Q. The charge of the atom containing 17 protons, 18 neutrons and 18 electrons is:

1. -2
2. -1
3. zero
4. 1

Q.

Compare all the proposed models of an atom.

Q. Atoms contain protons, neutrons and electrons. The mass of a neutron is assumed to be half of its original value while that of an electron is assumed to be twice of the original value. Calculate the change in atomic mass of carbon ($C^{12}$).

1. 25 % more
2. 75 % less
3. 50 % more
4. 25 % less

Q. An element is represented by ${}_Z{X}^A$, where Z is atomic number which is also equal to number of proton, A is mass number and X is symbol of the element.
Mass number (A) = Number of protons (Z) + Number of neutrons.
Isotopes: Atoms having same number of proton
Isobar: Elements having same mass number
Isotones: Elements having same number of neutron (A-Z)

Which of the following is a pair of isobar?

1. ${}_7{N}^{15},{}_8{O}^{16}$
2. ${}_6{C}^{13},{}_7{N}^{14}$
3. ${}_7{N}^{13},{}_8{O}^{15}$
4. ${}_6{C}^{13},{}_7{N}^{13}$

Q. The lightest particle among the following is:

1. Proton
2. Neutron
3. $\alpha$ particle
4. Positron

Q. Which of the following statements is incorrect for anode rays?

1. Anode rays travel in a straight line in the absence of electric and magnetic fields
2. They travel from anode to cathode
3. The e/m ratio of anode rays is constant
4. They are produced by the ionization of the gas in the discharge tube

Q. The fraction of volume occupied by the nucleus with respect to the total volume of an atom is:

1. ${10}^{-15}$
2. ${10}^{-5}$
3. ${10}^{-30}$
4. ${10}^{-10}$

Q. The electrochemical equivalent of copper is 0.0003296 g coulomb-1. Calculate the amount of copper deposited by a current of 0.5 ampere flowing through copper sulphate solution for 50 minutes.

1. 0.4944 g

2. 0.065 g

3. 2.87 g

4. 1.6 g

Q.

Mention the specific charge of proton.

Q.

Is Neutron Positive Or Negative.

Q. Taking the reference to be the corner particles for a fcc lattice, the number of second nearest atoms and the distance between them is, respectively :
Here,
r is the radius of the atom

1. $6\text{and}\frac{4r}{\sqrt{2}}$
2. $12\text{and}\frac{4r}{\sqrt{3}}$
3. $8\text{and}\frac{4r}{\sqrt{2}}$
4. $8\text{and}\frac{4r}{\sqrt{3}}$

Q. The increasing order for the magnitude of e/m (charge/mass) for an electron (e), proton (p), neutron (n) and an alpha-particle ($\alpha$) is:

1. e < p < n < $\alpha$
2. n < p < e < $\alpha$
3. n < p < $\alpha$ < e
4. n < $\alpha$ < p < e

Q. Find the approximate size of the nucleus of Nickel.
(Mass number = 59 Atomic number = 28)

1. 3 fm
2. 4 fm
3. 2 fm
4. 5 fm

Q.

How was the nucleus was discovered?

Q. Let mass of electron is half, mass of proton is two times and mass of neutron is three fourth of original masses. Then new atomic weight of O^{​​​​​​16} atom :-
A. Increase by 37.5%. B. Remain constant
C. Increase by 12.5%. D. Decrease by 25%

Q.

Calculate the formula unit mass of ${\mathrm{K}}_2{\mathrm{CO}}_3$.

Q. Which of the following are the correct statements regarding discovery of neutrons?

1. alpha particle were bombarded on beryllium foil to emit neutron and form carbon
2. The particles produced show deflection in presence of magnetic field.
3. Paraffin wax wall is used to absorb neutrons
4. alpha particle were bombarded on beryllium foil to emit neutron and form oxygen

Q.

(b) How cathode rays are formed from the gas taken in the discharge tube?

Q.

Atomic number and mass number of an element are 15 and 31 respectively. Calculate the number of electrons, protons and neutrons.

Q. A light paddle wheel is placed in the path of cathode rays in a cathode ray discharge tube experiment and it was found that cathode rays rotate the paddle wheel.
This observation leads to which of the following conclusions:

1. Cathode rays are negatively charged
2. Cathode rays are positively charged
3. All of the above
4. Cathode rays contain material particles having both mass and velocity

Q. The absolute mass of a neutron is:

1. Half of the mass of an electron
2. Twice the mass of a proton
3. Slightly greater than the mass of a proton
4. Equal to the mass of an electron

Q.

Does cathode ray pass through only if the anode has perforations?

can't the cathode ray just pass through the anode?

Q. Which of the following is the main cause for the late discovery of neutrons?

1. Neutrons in the nucleus move very fast
2. Neutrons do not possess any charge
3. All of these
4. Neutrons are heavier than proton

Q. Neutrons were discovered by:

1. J.J. Thomson
2. E. Rutherford
3. E. Goldstein
4. J. Chadwick

Q.

Ratio of frequency of revolution of electron in the second excited state of $H{e}^{\oplus }$ and second state of hydrogen is

1. 

2. 

3. 

4. 

Q.

What is the difference between amu and atomic weight in grams for an element

Q. Shown below is the cathode ray tube experimental setup.The green glow as shown is due to which material?

1. $ZnS$
2. $ZnC{l}_2$
3. $AgCl$
4. $FeS{O}_4$