3546: Protective action against harmful household insects and pests can be taken by the use of
(a) Infrasonic waves
(b) Microwaves
(c) Ultrasonic waves
(d) Low frequency radio waves
3547: Which of the following weather conditions is indicated by a sudden fall in barometer reading ?
(a) Stormy weather
(b) Calm weather
(c) Cold and dry weather
(d) Hot and sunny Weather
3548: A "closed economy" is an economy in which
(a) Only exports take place
(b) Neither exports nor imports take place
(c) Deficit financing takes place
(d) The money supply is fully controlled
3549: A boat filled with some stones is floating in water. If the stones are dropped into the water, the level of the water will
(a) Rise
(b) Decrease
(c) Remain the same
(d) Insufficient data to predict
3550: Which amongst the following provided a common factor for tribal insurrection in India in the 19th century ?
(a) Influence of rise of a large number of money lenders, traders and revenue farmers as middlemen in tribal areas
(b) The complete disruption of the old agrarian order of the' tribal communities
(c) Influence of foreign religious missionaries in tribal areas
(d) Introduction of a new system of land revenue and taxation of tribal products