Introduction Of Nucleus, Isotopes, Isobars, Isotones, A.M.V, Mass Defect, Binding Energy (Board Level)

1.

The nuclear radius of Pb²⁰⁸ is 8.874 fm. What will be the nuclear radius of Ca⁴⁴?

(a) 5. 483fm

(b) 5.286 fm

(c) 0.146 fm

(d) 4.326 fm

Ans (b)

2.

The mass defect for the nucleus of helium is 0.0303u. What is the binding energy per nucleus for helium in MeV?

(a)28 

(b)7   

(c)4   

(d)1.

Ans  (b)

3.

If M is atomic mass, A is mass number, then \left( {\frac{{M-A}}{M}} \right) is called

(a)Binding energy                

(b)Fermi energy                   

(c)Mass defect                     

(d)Packing fraction.

Ans  (d)

4.

The more readily fissionable isotope of uranium has an atomic mass of

(a)238u    

(b)236u   

(c)235u    

(d)234u.

Ans (c)

5.

Fusion reactions takes place at about

(a)3 × 10² K                                    

(b)3 × 10³ K                                    

(c)3 × 10⁴ K                                     

(d)3 × 10⁶ K.

Ans  (d)

6.

The mass density of a nucleus varies with mass number A as

(a)A² 

(b)A  

(c)constant                                    

(d)1/A

Ans (c)

7.

In nuclear fission, 0.1 % mass is converted into energy. The energy released by the fission of 1 kg mass is

(a)2.5 × 10⁵ k Wh                         

(b)2.5 × 10⁷ k Wh                         

(c)2.5 × 10⁶ k Wh                         

(d)2.5 × 10^–7 k Wh.

Ans (b)

8.

In a given nuclear reaction ₂He⁴ + _Z X _____ _Z+2Y ^{A + 3} + K, K is

(a) electron                                   

(b) positron                                   

(c) proton                                       

(d) neutron

Ans (d)

9.

A nucleus with A = 235 splits into two nuclei whose mass numbers are in the ratio 2 : 1. If R₀ = 1.4 fm, find the radii of the new nuclei.

(a) 5.99 fm, 1.45 fm

(b) 5.99 fm, 0.23 fm

(c) 5.99 fm, 8.36 fm

(d) 5.99 fm, 7.55 fm

Ans (d)

10.

Calculate the binding energy per nucleon for a ₆C¹² nucleus. Atomic mass of ₆C¹² = 12u, mass of a proton = 1.007825u, mass of a neutron = 1.008665u.

(a) 1.00 MeV

(b) 7.68 MeV

(c) 2.33 MeV

(d) 0.32 MeV

Ans (b)

11.

A nuclear reaction used U²³⁵ as fuel as an output of 10⁶ W. How much uranium is consumed per hour? The energy released per fission is 200 MeV. Given Avogadro’s number = 6.023 × 10²³ mol^–1.

(a) 1.0354 g

(b) 0.025 g

(c) 0.0439 g

(d) 2.2339 g

Ans (c)