A Metallic Sheet Has a Large Number of Slits, 5

question 48

Multiple Choice

A metallic sheet has a large number of slits, 5.0 mm wide and 20 cm apart, and is used as a diffraction grating for microwaves. A wide parallel beam of microwaves is incident normally on the sheet. What is the smallest microwave frequency for which only the central maximum occurs? (c = 3.00 × 10⁸ m/s)

• A) 0.50 GHz
• B) 0.70 GHz
• C) 1.0 GHz
• D) 1.5 GHz
• E) 2.0 GHz