Current Electri...

The smallest temperature difference that can be measured with a combination of a thermocouple of thermo e.m.f. 30µV per degree and a galvanometer of 50 ohm resistance, capable of measuring a minimum current of 3 × 10^–7 amp is

Antimony and bismuth are usually used in a thermocouple, because

Above neutral temperature, thermo e.m.f. in a thermocouple

For a thermocouple the neutral temperature is 270°C when its cold junction is at 20°C. What will be the neutral temperature and the temperature of inversion when the temperature of cold junction is increased to 40°C?

Consider the following two statements A and B and identify the correct choice given in the answers
A. Duddells thermo-galvanometer is suitable to measure direct current only
B. Thermopile can measure temperature differences of the order of 10^–3° C

The inversion temperature of a copper-iron thermocouple is 540° C when the cold junction temperature is 0° C. If the cold junction temperature is increased by 10° C, then the inversion temperature and neutral temperature of the thermocouple respectively are

The resistance of the filament of an electric bulb changes with temperature. If an electric bulb rated 220 volt and 100 watt is connected to (220 × 0.8) volt sources, then the actual power would be

An immersion heater is rated 836 watt. It should heat 1 litre of water from 10° C to 40° C in about

A house is served by 220 V supply line in a circuit protected by a 9 ampere fuse. The maximum number of 60 W lamps in parallel that can be turned on, is

Water boils in an electric kettle in 15 minutes after switching on. If the length of the heating wire is decreased to 2/3 of its initial value, then the same amount of water will boil with the same supply voltage in