PHYSICAL SCIENCES

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41. The resolution of a Michelson interferometer operating with a light source of 640 nm
wavelength is

1. 1280 nm.
2. 640 nm.
3. 80 nm.
4. 1 nm.

42. When a terminal is at virtual ground, then

1. both current and voltage are zero.
2. only voltage will be zero.
3. only current will be zero.
4. both voltage and current are not zero.

43. Platinum resistor (PTR) and a thermistor(THR) are used to measure room temperature.
Which of the following is true?

1. PTR offers more accuracy, THR more resolution.
2. PTR offers more resolution, THR more accuracy.
3. Both offer same accuracy, THR offers more resolution.
4. Both offer same resolution, PTR offers more accuracy.

44. A four bit A/D converter is used to convert an analog voltage of 8V. The maximum error is

1. 0.5 V.
2. 1.0 V.
3. 2.0 V.
4. 0.25 V.