While worship in the Temple in Jerusalem included musical instruments (2 Chronicles 29:2527), traditional Jewish religious services in the Synagogue, both before and after the last destruction of the Temple, did not include musical instruments given the practice of scriptural cantillation. The use of musical instruments is traditionally forbidden on the Sabbath out of concern that players would be tempted to repair (or tune) their instruments, which is forbidden on those days. (This prohibition has been relaxed in many Reform and some Conservative congregations.) Similarly, when Jewish families and larger groups sing traditional Sabbath songs known as zemirot outside the context of formal religious services, they usually do so a cappella, and Bar and Bat Mitzvah celebrations on the Sabbath sometimes feature entertainment by a cappella ensembles. During the Three Weeks musical instruments are prohibited. Many Jews consider a portion of the 49-day period of the counting of the omer between Passover and Shavuot to be a time of semi-mourning and instrumental music is not allowed during that time. This has led to a tradition of a cappella singing sometimes known as sefirah music.
What is part of the time between Passover and Shavuot thought to be?
a time of semi-mourning

The head of state of Delhi is the Lieutenant Governor of the Union Territory of Delhi, appointed by the President of India on the advice of the Central government and the post is largely ceremonial, as the Chief Minister of the Union Territory of Delhi is the head of government and is vested with most of the executive powers. According to the Indian constitution, if a law passed by Delhi's legislative assembly is repugnant to any law passed by the Parliament of India, then the law enacted by the parliament will prevail over the law enacted by the assembly.
Which government position is given most of the executive powers over Delhi?
Chief Minister of the Union Territory of Delhi

Occupancy sensors to allow operation for whenever someone is within the area being scanned can control lighting. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned. Doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Ultrasonic sensors transmit sound above the range of human hearing and monitor the time it takes for the sound waves to return. A break in the pattern caused by any motion in the area triggers the control. Ultrasonic sensors can see around obstructions and are best for areas with cabinets and shelving, restrooms, and open areas requiring 360-degree coverage. Some occupancy sensors utilize both passive infrared and ultrasonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures.
What type of sensor transmits sound above the range of human hearing?
Ultrasonic sensors