Answer : To avoid the effect of stray magnetic field in A.C. bridges we can use magnetic screening.
Description : Can the electric field between two positive charges be zero?
Answer : It can only if they have equal charges.
Description : Derive an expression for energy stored in a magnetic field .
Answer : Expression for energy stored in a magnetic field: The energy is stored in magnetic field when current increases and return back when the current decreases. At instant t' seconds after closer of switch ... energy absorbed by the magnetic field when current increases from 0 to I amperes
Description : What arc the errors occurring in measuring devices due to stray magnetic field and temp '? Explain how to compensate them.
Answer : 1. Error due to stray magnetic fields- Main magnetic field gets disturbed by external magnetic fields known as stray magnetic fields. 2. Compensation technique To avoid this error, ... resistance alloy having a negligible resistance temp coefficient in the ratio of 1:10 for pressure coil
Description : Why does the magnetic field flow from north to south?