In an electric circuit, ammeter is connected in MCQ with Answer and Explanation

Explanation:
T = 1/60 s.

Explanation:
Visible spectrum: red ~700 nm, orange, yellow, green, blue, indigo, violet ~400 nm. Red has longest wavelength, lowest frequency. Violet shortest wavelength, highest frequency. Remember VIBGYOR.

Explanation:
Significant figures rules: leading zeros are not significant; trailing zeros after decimal are significant. Thus 0.00250: leading zeros (before 2) not significant; digits 2,5,0 are significant (trailing zero after decimal counts). So three significant figures. Memory tip: 'Start counting at first non-zero digit; include trailing zeros after decimal'. This measurement precision concept is frequently tested in competitive exams. Always apply rules consistently: 0.0025 has two sig figs; 0.00250 has three, indicating higher precision.