To use an ammeter as a voltmeter you place a high resistance in series; among given choices the intended correct description is adding resistance in series (option A interpreted as series low was OCR-corrupted but context requires series resistance).

Otto von Guericke is known for developing an early vacuum pump in the 17th century, making him the correct inventor.

Daniel Gabriel Fahrenheit developed the mercury thermometer around that period, making him the inventor of the closed-tube thermometer.

On an oscilloscope the vertical (y) axis represents voltage (volts) while the horizontal (x) axis represents time, so option B is correct.

Period = 54.6/30 = 1.82 s; uncertainty = least count/30 = 0.1/30 ≈ 0.003 s, so 1.82 ± 0.003 s.

For X = M^a L^b T^c, percentage errors add in magnitude: total percentage error = a% + b% + c% weighted by exponents, so the choice with all plus signs is correct.

Light is an electromagnetic wave whose oscillations are perpendicular to the direction of propagation, so it is transverse.

Resultant amplitude from vector addition is √(A1² + A2² + 2A1A2 cos(phase difference)).

Common gas lasers include helium-neon, argon-ion and neon variants, so the best choice is all of these.

Joseph von Fraunhofer identified and explained the dark lines (Fraunhofer lines) in the solar spectrum.