Suppose an alpha particle accelerated by a potential of V volt is allowed to collide with a nucleus of atomic number Z, then the distance of closest approach of alpha particle to the nucleus is _____.

(a)

\(14.4\frac { Z }{ V } \mathring { A } \)

(b)

\(14.4\frac { V }{ Z } \mathring { A } \)

(c)

\(1.44\frac { Z }{ V } \mathring { A } \)

(d)

\(1.44\frac { V }{ Z } \mathring { A } \)

Atomic number of H-like atom with ionization potential 122.4 V for n = 1 is _____.

(a)

1

(b)

2

(c)

3

(d)

4

The charge of cathode rays particle is _____.

(a)

Positive

(b)

negative

(c)

neutral

(d)

not defined

The ratio of the wavelengths radiation emitted for the transition from n = 2 to n = 1 in Li⁺⁺, He⁺ and H is _____.

(a)

1:2:3

(b)

1:4:9

(c)

3:2:1

(d)

4:9:36

If the nuclear radius of ²⁷Al is 3.6 fermi, the approximate nuclear radius of ⁶⁴Cu, in femi is _____.

(a)

2:4

(b)

1.2

(c)

4.8

(d)

3.6