Enter Einstein!

Q.

Einstein got Nobel prize on which of the following works

1. Mass-energy relation

2. Special theory of relativity

3. Photoelectric equation

4. (a) and (b) both

Q.

Einstein got Nobel prize on which of the following works

1. Mass-energy relation

2. Special theory of relativity

3. Photoelectric equation

4. (a) and (b) both

Q.

By photoelectric effect, Einstein, proved

1. $E=hv$

2. $K.E.=\frac{1}{2}m{v}^2$

3. $E=m{c}^2$

4. $E=\frac{Rh{c}^2}{n^2}$

Q. When the light of frequency $2{\nu }_0$ (where ${\nu }_0$ is a threshold frequency) is incident on a metal plate, the maximum velocity of electrons emitted is $v_1$. When the frequency of the incident radiation is increased to $5{\nu }_0$, the maximum velocity of electrons emitted from the same plate is $v_2$. The ratio of $v_1$ to $v_2$ is

1. 1 : 2
2. 1 : 4
3. 4 : 1
4. 2 : 1

Q.

The work function of a metal is

1. The energy for the electron to come out from metal surface

2. The energy for the electron to enter into the metal

3. The energy for producing X-ray

4. None of these

Q. When photons of energy 4.25 eV strike the surface of metal A, the ejected photoelectrons have maximum kinetic energy $T_A$ and de Broglie wavelength ${\lambda }_A.$ The maximum kinetic energy of photoelectrons liberated from another metal B by photons of energy 4.70 eV is $T_B=(T_A-1.50)eV.$ If the de Broglie wavelength of these photoelectrons is ${\lambda }_B=2{\lambda }_A,$ then

1. The work function of A is 2.25 eV
2. The work function of B is 4.20 eV
3. $T_A$= 2.00 eV
4. $T_B$ = 2.75 eV