What type of tremor occurs when a body part is placed in a particular position and required to maintain that position for a long period of time?

 The answer is Postural Tremor. Kinetic tremors occur during movement of a body part, such as moving your wrist up and down. Task-specific tremors occur during a particular activity, such as writing. A postural tremor transpires when holding a position against gravity, such as holding your arm or leg outspread.

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.