1221. Electric charge can be detected by which of the following instruments:
A. Electroscope *
D. None of these
1222. In which of the following we can not use alternating current?
B. Galvanometer *
1223. By the use of which of the following can the conversion of heat into electrical energy be achieved ?
B. Photoelectric tube
C. Thermo-Couple *
D. Triode valve
1224. Enriched Uranium, used in a nuclear reactor is _______.
A. Uranium alloy with Aluminium
B. Uranium that contains a particular isotope in high concentration
C. Uranium treated with radiation *
D. Uranium feed of all impurities
1225. Which one of the following is a common constituent of transistors?
C. Germanium *
1226. Safety wire used in electrical circuits is made of a material having .
A. Low melting point *
B. High resistance
C. High melting point
D. Low specific heat
1227. For which of the following is a diode used ?
D. Rectification *
1228. By the use of which of the following types of lens can myopia be corrected ?
B. Concave *
1229. How does a thermos keep the liquid hot for a long time?
A. It has an internal heating arrangement
B. Shinning inner walls and double walls of outer covering do not allow radiation of heat. *
C. It is packed with gases which release heat
D. None of these
1230. A hand pump water is cold in winters and warm in summers. Why?
A. It is due to the pressure exerted while taking out water
B. It is due hot gases under the earth
C. It is because of the temperature difference during winter the outside temperature is lower than that of the water which comes out from the ground. Reverse is the case in summers.
D. None of above