It's size is: Z (Height): 20 cmX and Y (Width): 10 cm
You can change power of the light bulb by Shade Editor (Shift F3) > NodeGroup > Emission (here 200)
BLEND (Blender, filesize: 4.13 MB), OBJ (OBJ, filesize: 621 Bytes), FBX (Autodesk FBX, filesize: 1.22 MB), ABC (Alembic, filesize: 2.58 MB), PLY (Ply, filesize: 1.79 MB), DAE (Collada, filesize: 8.98 MB)