Question

the correct answer is 260 m, which is lettered b, and therefore answer space b would be shade
=a= =b= =c= =d=
think carefully before you shade the answer spaces; erase completely any answers you wish to
do all rough work in this question paper.
now answer the following questions:
the phenomenon illustrated in the diagram below is
diagram: light energy hitting metal plate, electrons emitted
a. photoelectric effect.
b. thermionic emission.
c. reflection of light.
d. wave –particle paradox.

1. what temperature on the kelvin scale is equivalent to 10 °c change in celsius reading?

a. 263 k
b. 273 k
c. 283 k
d. 10 k

Explanation:

Question 1 (Phenomenon in Diagram)

The diagram shows light energy hitting a metal plate and electrons being emitted. The photoelectric effect is the emission of electrons from a material when light (electromagnetic radiation) is incident on it. Thermionic emission is electron emission due to heat, reflection of light involves bouncing light (not electron emission), and wave - particle paradox is about dual nature of light/matter, not this emission. So the correct option is A.

Step1: Recall the relationship between Kelvin (K) and Celsius (\(^\circ\text{C}\)) scales.

The formula to convert Celsius to Kelvin is \(T(K)=T(^\circ\text{C}) + 273\). But for a change in temperature, \(\Delta T(K)=\Delta T(^\circ\text{C})\) because the size of a Kelvin degree is the same as a Celsius degree.

Step2: Analyze the problem.

We are asked for the temperature on the Kelvin scale equivalent to a \(10^\circ\text{C}\) change. Wait, no, actually, if we consider a temperature value: Wait, no, the question is a bit misphrased? Wait, no, maybe it's a change? Wait, no, looking at the options, let's re - evaluate. Wait, maybe the question is: What temperature on the Kelvin scale is equivalent to \(10^\circ\text{C}\) (as a temperature, not a change)? Wait, no, the options: Let's check the conversion. \(T(K)=T(^\circ\text{C})+273\). So for \(T(^\circ\text{C}) = 10\), \(T(K)=10 + 273=283\ K\). But if it's a change, \(\Delta T(K)=\Delta T(^\circ\text{C})\), so a \(10^\circ\text{C}\) change is a \(10\ K\) change. But the options have 283 K as an option (option C). So probably the question is asking for the temperature when \(T(^\circ\text{C})=10\), so \(T(K)=10 + 273 = 283\ K\).

Answer:

A. photoelectric effect.

Question 2 (Kelvin and Celsius Temperature Change)