Problem 84
Which of the following explains the increase of the reaction rate by catalyst: (a) Catalyst decreases the rate of backward reaction so that the rate of forward reaction increases (b) Catalyst provides extra energy to reacting molecules so that they may reduce effective collisions (c) Catalyst provides an alternative path of lower activation energy to the reactants (d) Catalyst increases the number of collisions between the reacting molecules.
Problem 85
Collision theory is satisfactory for: (a) First order reactions (b) Zero order reactions (c) Bimolecular reactions (d) Any order reactions
Problem 92
The radiation from naturally occurring radioactive substance as seen atter derlection by a magnetic field in one direction are : (a) \(\alpha\) -rays (b) \(\beta\) -rays (c) both \(\alpha\) and \(\beta\) rays (d) either \(\alpha\) or \(\beta\) -rays
Problem 95
Consider the following decay \({ }_{z} X^{A} \rightarrow_{z+1} Y^{A}+{ }_{-1} e^{0}, X\) is unstable because : (a) its nucleus has excess energy (b) \(\frac{n}{p}\) ratio is high (c) \(\frac{n}{p}\) ratio is low (d) none of these
Problem 98
Which of the following processes causes the emission of X-ray? (a) \(\alpha\) -emission (b) \beta-emission (c) \(\beta^{+}\) (Positron emission) (d) electron capture
Problem 100
a........ is produced when a positron and an electron collide. (a) \(X\) -ray (b) Neutron (c) \(\gamma\) -radiation (d) Neutrino
Problem 103
Loss in \(\beta\) -particle is equivalent to : (a) increase of one proton only (b) decrease of one neutron only (c) both (a) and (b) (d) none of these
Problem 105
\({ }_{90} \mathrm{Th}^{234}\) disintegrate to give \({ }_{82} \mathrm{~Pb}^{206}\) as the final product. Total no. of \(\alpha\) and \(\beta\) particles emitted out during this process are : (a) 6 (b) 7 (c) 8 (d) 13
Problem 107
Pair of isobar is : (a) \({ }_{6} \mathrm{C}^{13},{ }_{7} \mathrm{~N}^{13}\) (b) \({ }_{6} \mathrm{C}^{13},{ }_{7} \mathrm{~N}^{14}\) (c) \({ }_{6} \mathrm{C}^{14} ;{ }_{8} \mathrm{~N}^{15}\) (d) none of these
Problem 108
Isodiaphers are atoms having: (a) \(n / p\) constant (b) \(p / n\) constant (c) \((n-p)\) constant (d) \((n-p)\) different
