`{:("Column I","","Column II"),((a)" " "All electromagnetic waves including visible light", (p), "microwaves"),((b)" ""Electromagnetic waves whose frequency is in the range 500 kHz to 1000 MHz ",(q),"have the same speed c in vacuum"),((c)" " "The force exerted by an electromagnetic wave on unit area of surface", (r)," radio waves "),((d)" ""The shortest wavelength radio waves",(s), "radiation pressure") :}`

Answer

To solve the matching question, we need to connect the items in Column I with the appropriate items in Column II based on our understanding of electromagnetic waves. Let’s analyze each item step by step:

### Step 1: Analyze Item (a)
**Column I:** All electromagnetic waves including visible light
**Column II Options:** (p) microwaves, (q) have the same speed c in vacuum

- All electromagnetic waves, including visible light, travel at the same speed (c) in a vacuum. Therefore, the correct match for (a) is (q).

### Step 2: Analyze Item (b)
**Column I:** Electromagnetic waves whose frequency is in the range 500 kHz to 1000 MHz
**Column II Options:** (r) radio waves

- The frequency range of 500 kHz to 1000 MHz corresponds to radio waves. Thus, the correct match for (b) is (r).

### Step 3: Analyze Item (c)
**Column I:** The force exerted by an electromagnetic wave on unit area of surface
**Column II Options:** (s) radiation pressure

- The force per unit area exerted by an electromagnetic wave is known as radiation pressure. Therefore, the correct match for (c) is (s).

### Step 4: Analyze Item (d)
**Column I:** The shortest wavelength radio waves
**Column II Options:** (p) microwaves

- Among radio waves, the shortest wavelength is associated with microwaves. Thus, the correct match for (d) is (p).

### Summary of Matches
- (a) → (q): All electromagnetic waves including visible light have the same speed c in vacuum.
- (b) → (r): Electromagnetic waves whose frequency is in the range 500 kHz to 1000 MHz are radio waves.
- (c) → (s): The force exerted by an electromagnetic wave on unit area of surface is radiation pressure.
- (d) → (p): The shortest wavelength radio waves are microwaves.

### Final Matches
- (a) → (q)
- (b) → (r)
- (c) → (s)
- (d) → (p)

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