Product of two numbers = HCF x LCM

Q.

The work function for metals A, B and C are respectively 1.92 eV, 2.0 eV and 5 eV. According to Einstein’s equation, the metals which will emit photo electrons for a radiation of wavelength $4100\stackrel{\circ }{A}$ is/are

1. None of these

2. A and B only

3. All the three metals

4. A only

Q.

Explain Hertz and Lenards observation of the photoelectric effect.

Q.

The work function of a photoelectric material is 3.3 eV. The threshold frequency will be equal to

1. $8\times {10}^{4}Hz$

2. $8\times {10}^{56}Hz$

3. $8\times {10}^{10}Hz$

4. $8\times {10}^{14}Hz$

Q. Work function of a metal is 2.51 eV. Its threshold frequency is

1. $5.9\times {10}^{14}Cycle/sec$.
2. $6.5\times {10}^{14}Cycle/sec$.
3. $9.4\times {10}^{14}Cycle/sec$.
4. $6.8\times {10}^{14}Cycle/sec$.

Q. The minimum energy required to remove an electron is called

1. Kinetic energy
2. Stopping potential
3. Work function
4. None of these

Q.

The electrons are emitted in the photoelectric effect from a metal surface

1. Only if the frequency of the incident radiation is above a certain threshold value

2. Only if the temperature of the surface is high

3. At a rate that is independent of the nature of the metal

4. With a maximum velocity proportional to the frequency of the incident radiation

Q.

Statement 1: It was surprising for the scientist to observe that photocurrent depends on the frequency of the light.

Statement 2: According to the wave model , Energy of the light falling on the plate depends only on the amplitude of Light and not on frequency , so they assumed that changing frequency shouldn't change anything.

1. Statement 1 is true but statement 2 is false.

2. Statement 1 and 2 both are false.

3. statement 1 is true and statement 2 is the correct reason for it.

4. Statement 1 is true but statement 2 is not the correct reason for it

Q.

The frequency and work function of an incident photon are v and ${\varphi }_0$. If $v_0$ is the threshold frequency then necessary condition for the emission of photo electron is

1. $Noneofthese$

2. $v<v_0$

3. $v\ge v_0$

4. $v=\frac{v_0}{2}$