**Answer:**

0 MN/C, 2.697 MV

4.1953 MN/C, 1.2586 MV

19.2642857143 MN/C, 2.697 MV

**Explanation:**

k = Coulomb constant =

Electric field at r = 8 cm

E = 0 (inside)

Electric potential is given by

**Electric potential is 2.697 MV**

r = 30 cm

**Electric field is 4.1953 MN/C**

**Electric potential is 1.2586 MV**

r = R = 14 cm

**The electric field is 19.2642857143 MN/C**

**The potential is 2.697 MV**

Guglielmo Marconi invented the first radio transmitter.

Since he is not one of the options, I would go with B. Hertz.

Marconi started his research after Hertz’s experiments and work in electromagnetic waves.

Interpersonal communication.

It's a conversation between two people and no one else.

**Answer:**

<em>**2.72 x 10^-43 m**</em>

<em></em>

**Explanation:**

mass of the telescope = 7500 kg

speed of the telescope = 3.25 x 10^5 m/s

de Broglie's wavelength of the telescope is given as

λ = h/mv

where

λ is the wavelength of the telescope

h is the plank's constant = 6.63 × 10-34 m^2 kg/s

m is the mass of the telescope = 7500 kg

v is speed of the telescope = 3.25 x 10^5 m/s

substituting value, we have

λ = (6.63 × 10-34)/(7500 x 3.25 x 10^5)

λ = <em>**2.72 x 10^-43 m**</em>