A radio signal will travel around the earth (in a great circle) in about ______?

ایک ریڈیو سگنل تقریبا ______ میں زمین کے گرد (ایک عظیم دائرے میں) سفر کرے گا؟

Instantly

2 second

1/7 second

None of these

Radio Wave Speed: ~300,000 km/s (speed of light).

Earth's Circumference: ~40,000 km.

Time to Circle Earth: ~0.133 sec (~1/7 sec).