Store text from file in character array using fread()

Here is a minimal "working" example:

#include <stdio.h>
#include <stdlib.h>

int main (int argc, char* argv[])
{
    int num = 10;

    FILE* fp = fopen("test.txt", "r");     // test.txt contains character sequence

    char* ptr = (char*) malloc(sizeof (char)*(num+1));  // +1 for '\0'

    fread(ptr, sizeof(char), num, fp);      // read bytes from file
    ptr[num] = '\0';

    printf("%s\n", ptr);        // output: ´╗┐abcdefg

    free(ptr);
    fclose(fp);

    return 0;
}

I would like to read some letters from a text file, containing all letters from the alphabet in a single line. I want my array to store the first 10 letters, but the first 3 shown in the output are weird symbols (see the comment at the printf statement).

What am I doing wrong?