question_data = `{
    "title": " TEST 9 GOC Wave propagation 3",
    "buttonText": "Klicka här för att rätta",
    "questions": [{
            "number": "1",
            "question": "The skip distance of radio signals is determined by the:  ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": "type of transmitting antenna used "
                }, 
                {
                    "label": "b",
                    "text": " power fed to the final amplifier of the transmitter"
                }, 
                {
                    "label": "c",
                    "text": "only the angle of radiation from the antenna "
                }, 
                {
                    "label": "d",
                    "text": " both the height of the ionosphere and the angle of radiation from the antenna"
                }]
        }, {
            "number": "2",
            "question": "Three recognised layers of the ionosphere that affect radio propagation are:  ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": "A, E, F "
                }, 
                {
                    "label": "b",
                    "text": " B, D, E "
                }, 
                {
                    "label": "c",
                    "text": " C, E, F "
                }, 
                {
                    "label": "d",
                    "text": " D, E, F "
                }]
        }, {
            "number": "3",
            "question": " The distance from the transmitter to the nearest point where the sky wave returns to the earth is called the: ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": "angle of radiation  "
                }, 
                {
                    "label": "b",
                    "text": "maximum usable frequency  "
                }, 
                {
                    "label": "c",
                    "text": "skip distance "
                }, 
                {
                    "label": "d",
                    "text": "skip zone "
                }]
        }, {
            "number": "4",
            "question": "A variation in received signal strength caused by slowly changing differences in path lengths is called:   ",
            "correct": "b",
            "answer": [
                {
                    "label": "a",
                    "text": "absorption  "
                }, 
                {
                    "label": "b",
                    "text": "fading  "
                }, 
                {
                    "label": "c",
                    "text": "fluctuation "
                }, 
                {
                    "label": "d",
                    "text": "path loss  "
                }]
        }, { 
            "number": "5",
            "question": " VHF and UHF bands are frequently used for satellite communication because:  ",
            "correct": "a",
            "answer": [
                {
                    "label": "a",
                    "text": "waves at these frequencies travel to and from the satellite relatively unaffected by the ionosphere  "
                }, 
                {
                    "label": "b",
                    "text": " the Doppler frequency change caused by satellite motion is much less than at HF "
                }, 
                {
                    "label": "c",
                    "text": "satellites move too fast for HF waves to follow  "
                },
                {
                    "label": "d",
                    "text": "the Doppler effect would cause HF waves to be shifted into the VHF and UHF bands. "
                }]
        }, {
            "number": "6",
            "question": "The 'critical frequency' is defined as the:   ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": " highest frequency to which your transmitter can be tuned "
                }, 
                {
                    "label": "b",
                    "text": " lowest frequency which is reflected back to earth at vertical incidence "
                }, 
                {
                    "label": "c",
                    "text": " minimum usable frequency "
                }, 
                {
                    "label": "d",
                    "text": " highest frequency which will be reflected back to earth at vertical incidence "
                }]
        }, {
            "number": "7",
            "question": " The speed of a radio wave:  ",
            "correct": "b",
            "answer": [
                {
                    "label": "a",
                    "text": " varies indirectly to the frequency "
                }, 
                {
                    "label": "b",
                    "text": "is the same as the speed of light "
                }, 
                {
                    "label": "c",
                    "text": " is infinite in space "
                }, 
                {
                    "label": "d",
                    "text": "is always less than half the speed of light  "
                }]
        }, {
            "number": "8",
            "question": " The MUF for a given radio path is the: ",
            "correct": "b",
            "answer": [
                {
                    "label": "a",
                    "text": " mean of the maximum and minimum usable frequencies "
                }, 
                {
                    "label": "b",
                    "text": " maximum usable frequency "
                }, 
                {
                    "label": "c",
                    "text": " minimum usable frequency "
                }, 
                {
                    "label": "d",
                    "text": " mandatory usable frequency "
                }]
        }, {
            "number": "9",
            "question": " The position of the E layer in the ionosphere is:  ",
            "correct": "b",
            "answer": [
                {
                    "label": "a",
                    "text": "above the F layer  "
                }, 
                {
                    "label": "b",
                    "text": "below the F layer "
                }, 
                {
                    "label": "c",
                    "text": "below the D layer  "
                }, 
                {
                    "label": "d",
                    "text": "sporadic  "
                }]
        }, {
            "number": "10",
            "question": " Skip distance is a term associated with signals through the ionosphere. Skip effects are due to: ",
            "correct": "a",
            "answer": [
                {
                    "label": "a",
                    "text": " reflection and refraction from the ionosphere "
                }, 
                {
                    "label": "b",
                    "text": " selective fading of local signals "
                }, 
                {
                    "label": "c",
                    "text": " high gain antennas being used "
                }, 
                {
                    "label": "d",
                    "text": "local cloud cover "
                }]
        }, {
            "number": "11",
            "question": " The type of atmospheric layers which will best return signals to earth are:  ",
            "correct": "c",
            "answer": [
                {
                    "label": "a",
                    "text": "oxidised layers  "
                }, 
                {
                    "label": "b",
                    "text": " heavy cloud layers "
                }, 
                {
                    "label": "c",
                    "text": "ionised layers  "
                }, 
                {
                    "label": "d",
                    "text": "sun spot layers "
                }]
        }, {
            "number": "12",
            "question": " The ionosphere:  ",
            "correct": "c",
            "answer": [
                {
                    "label": "a",
                    "text": " is a magnetised belt around the earth "
                }, 
                {
                    "label": "b",
                    "text": " consists of magnetised particles around the earth "
                }, 
                {
                    "label": "c",
                    "text": "is formed from layers of ionised gases around the earth "
                }, 
                {
                    "label": "d",
                    "text": " is a spherical belt of solar radiation around the earth "
                }]
        }, {
            "number": "13",
            "question": "The skip distance of a sky wave will be greatest when the:  ",
            "correct": "c",
            "answer": [
                {
                    "label": "a",
                    "text": "ionosphere is most densely ionised  "
                }, 
                {
                    "label": "b",
                    "text": "signal given out is strongest  "
                }, 
                {
                    "label": "c",
                    "text": "angle of radiation is smallest "
                }, 
                {
                    "label": "d",
                    "text": "polarisation is vertical "
                }]
        }, {
            "number": "14",
            "question": "If the height of the reflecting layer of the ionosphere increases, the skip distance of a high frequency transmission:  ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": " stays the same "
                }, 
                {
                    "label": "b",
                    "text": "decreases  "
                }, 
                {
                    "label": "c",
                    "text": " varies regularly "
                }, 
                {
                    "label": "d",
                    "text": "becomes greater  "
                }]
        }, {
            "number": "15",
            "question": " If the frequency of a transmitted signal is so high that we no longer receive a reflection from the ionosphere, the signal frequency is above the:  ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": "speed of light  "
                }, 
                {
                    "label": "b",
                    "text": " sun spot frequency "
                }, 
                {
                    "label": "c",
                    "text": "skip distance  "
                }, 
                {
                    "label": "d",
                    "text": "maximum usable frequency  "
                }]
        }, {
            "number": "16",
            "question": "A 'line of sight' transmission between two stations uses mainly the:   ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": " ionosphere "
                }, 
                {
                    "label": "b",
                    "text": "troposphere  "
                }, 
                {
                    "label": "c",
                    "text": "sky wave "
                }, 
                {
                    "label": "d",
                    "text": " ground wave "
                }]
        }, {
            "number": "17",
            "question": " The distance travelled by ground waves in air: ",
            "correct": "c",
            "answer": [
                {
                    "label": "a",
                    "text": "depends on the maximum usable frequency  "
                }, 
                {
                    "label": "b",
                    "text": " is the same for all frequencies "
                }, 
                {
                    "label": "c",
                    "text": "is less at higher frequencies "
                }, 
                {
                    "label": "d",
                    "text": "is more at higher frequencies "
                }]
        }, {
            "number": "18",
            "question": " The radio wave from the transmitter to the ionosphere and back to earth is correctly known as the:  ",
            "correct": "a",
            "answer": [
                {
                    "label": "a",
                    "text": "sky wave  "
                }, 
                {
                    "label": "b",
                    "text": " skip wave "
                }, 
                {
                    "label": "c",
                    "text": " surface wave "
                }, 
                {
                    "label": "d",
                    "text": " F layer "
                }]
        }, {
            "number": "19",
            "question": " Reception of high frequency radio waves beyond 4000 km normally occurs by the:  ",
            "correct": "d",
            "answer": [
                {
                    "label": "a",
                    "text": " ground wave "
                }, 
                {
                    "label": "b",
                    "text": " skip wave "
                }, 
                {
                    "label": "c",
                    "text": " surface wave "
                }, 
                {
                    "label": "d",
                    "text": " sky wave "
                }]
        }, {
            "number": "20",
            "question": "The number of high frequency bands open to long distance communication at any time depends on:   ",
            "correct": "a",
            "answer": [
                {
                    "label": "a",
                    "text": "the highest frequency at which ionospheric reflection can occur  "
                }, 
                {
                    "label": "b",
                    "text": "the number of frequencies the receiver can tune  "
                }, 
                {
                    "label": "c",
                    "text": " the power being radiated by the transmitting station "
                }, 
                {
                    "label": "d",
                    "text": "the height of the transmitting antenna "
                }]
        }]
}`;