• Radius Of Singly Ionized Helium
• Singly Ionized Helium Atom Electron
• Helium Charge
• Second Ionization Energy Of Helium
• Mass Of Singly Ionized Helium

Explanation: A helium atom He contains two electrons. Removing one of the two electrons produces a He+ ion. The ion would be left with one single electron and is isoelectric to a hydrogen atom. Helium (He) Persistent Lines of Singly Ionized Helium (He II).

A

$lambda_1$ =$lambda_2 =4 lambda_3 = 9lambda_4$

B

$4lambda_1 = 2lambda_2 = 2lambda_3 =lambda_4$

C

$lambda_1 = 2lambda_2 =2 surd 2 lambda_3 = 3 surd 2 lambda_4$

D

$lambda_1 = lambda_2 =2lambda_3 =surd 2lambda_4$

Solution:

$Z_{1:}=:1,:Z_2:=:1,:Z_3:=:2:and:Z_4:=3.:$
$:frac{1}{lambda }:=:RZ^2left(frac{1}{1^2}:-:frac{1}{2^2}right):or:::::::lambda :=frac{4}{3RZ^2}:$
$:or:::::lambda Z^2:=:constant::$
$:So::lambda _1left(1right)^2:=:lambda _2:left(1right)^2:=:lambda _3left(2right)^2:=:lambda aleft(3^2right):$
$:or:lambda _1:=:lambda _1:lambda _2:=:4lambda _3:=:9lambda _{4.}$

1. When a metal surface is illuminated by light ofwavelengths 400 nm and 250 nm, the maximum
velocities of the photoelectrons ejected are v and2v respectively.
The work function of the metal is(h - Planck's constant, c = velocity of light in air)

2. Two conducting shells of radius a and b areconnected by conducting wire as shown in figure.The capacity of system is :

3. When $_{92}U^{235}$ undergoes fission, 0.1% of its
original mass is changed into energy. How much
energy is released if 1 kg of $_{92}U^{235}$ undergoesfission

Radius Of Singly Ionized Helium

4. One mole of an ideal gas is taken from state A tostate B by three different processes,
(i) ACB (ii) ADB (iii) AEB as shown in the P-Vdiagram. The heat absorbed by the gas is.

5. In the formula$ X = 3 YZ^2, X $and Z have dimensions
of capacitance and magnetic induction respectively.
The dimensions of Y in MKSA systemare :

6. Two very long, straight, parallel wires carry steadycurrents I and -I respectively. The distancebetween the wires is d.
At a certain instant oftime, a point charge q is at a point equidistantfrom the two wires, in the plane of the wires.
Itsinstantaneous velocity v is perpendicular to thisplane. The magnitude of the force due to themagnetic field acting on the charge at this instantis.

7. Two projectiles A and B thrown with speeds in the ratio$ 1 :sqrt{ 2}$ acquired the same heights. If A is thrown at an angle of $45^circ$ with the horizontal, the angle of projection of B will be

8. A meter bridge is set up as shown, to determinean unknown resistance ‘X’ using a standard 10ohm resistor.
The galvanometer shows null pointwhen tapping-key is at 52 cm mark.
The endcorrectionsare 1 cm and 2 cm respectively for theends A and B.
The determined value of ‘X’ is

9. A disk of radius a / 4 having a uniformlydistributed charge 6 C is placed in the x - y planewith its centre at (-a / 2, 0, 0). A rod of length acarrying a uniformly distributed charge 8 C isplaced on the x-axis from x = a /4 to x = 5a / 4.
Two point charges - 7 C and 3 C are placed at (a/ 4, - a /4, 0) and (- 3a /4, 3a / 4, 0), respectively.
Consider a cubical surface formed by six surfaces$x = ± a / 2, y = ± a / 2, z = ± a / 2$. The electric fluxthrough this cubical surface is

10. A particle of mass m moving in the x directionwith speed 2v is hit by another particle of mass2m moving in the y direction with speed v. If thecollision is perfectly inelastic, the percentage lossin the energy during the collision is close to

1. The phase difference between displacement and acceleration of a particle in a simple harmonic motion is:

2. A cylinder contains hydrogen gas at pressure of 249 kPa and temperature $27^circ,C$. Its density is :$(R = 8.3,J,mol^{-1}K^{-1}$)

3. The solids which have negative temperature coefficient of resistance are :

Singly Ionized Helium Atom Electron

4. The energy equivalent of 0.5 g of a substance is:

5. The Brewsters angle $i_b$ for an interface should be:

6. Two cylinders A and B of equal capacity are connected to each other via a stop clock. A contains an ideal gas at standard temperature and pressure. B is completely evacuated. The entire system is thermally insulated. The stop cock is suddenly opened. The process is:

7. A screw gauge has least count of 0.01 mm and there are 50 divisions in its circular scale.
The pitch of the screw gauge is:

8. For which one of the following, Bohr model is not valid?

Helium Charge

9. A body weighs 72 N on the surface of the earth. What is the gravitational force on it, at a height equal to half the radius of the earth?

Second Ionization Energy Of Helium

Mass Of Singly Ionized Helium

10. The refractive index of a particular material is 1.67 for blue light, 1.65 for yellow light and 1.63 for red light. The dispersive power of the material is .........