1
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

A particle at rest decays in to two particles of mass $$m_1$$ and $$m_2$$ and move with velocities $$v_1$$ and $$v_2$$. The ratio of their de Broglie wave length $$\frac{\lambda_1}{\lambda_2}$$ is:

A
1 : 4
B
1 : 1
C
1 : 2
D
2 : 1
2
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

An electron and a proton having mass $$m_e$$ and $$m_p$$ respectively, initially at rest, move through the same distance '$$s$$' in a uniform electric field '$$E$$'. If the time taken by them to cover that distance is $$t_e$$ and $$t_p$$ respectively, then $$t_e / t_p$$ is equal to:

A
$$ \sqrt{\left(\frac{m_p}{m_e}\right)} $$
B
$$ \sqrt{\left(\frac{m_e}{m_p}\right)} $$
C
$$ \frac{\sqrt{\left(m_e\right)}}{m_p} $$
D
$$ \frac{m_e}{m_p} $$
3
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

$$220 \mathrm{~V}$$ ac is more dangerous than $$220 \mathrm{~V}$$ dc Why?

A
The peak value of ac is greater than the given value of dc
B
Shock received from ac is always repulsive
C
The frequency of ac is more than that of dc
D
The speed of ac is more than that of $$\mathrm{dc}$$
4
COMEDK 2023 Evening Shift
MCQ (Single Correct Answer)
+1
-0

The ground state energy of hydrogen atom is $$-13.6 \mathrm{~eV}$$. If the electron jumps from the $$3^{\text {rd }}$$ excited state to the ground state then the energy of the radiation emitted will be:

A
1.275 MeV
B
12.75 eV
C
12.75 J
D
12.75 MeV
EXAM MAP