A barometer kept in an elevator reads 76cm when it is at rest. If the

1.	A barometer kept in an elevator reads 76cm when it is at rest. If the elevator goes up with increasing speed, the reading will be(a) zero (b) 76cm (c) < 76cm (d) > 76cm.
Answer» The correct answer is(c) < 76 cm EXPLANATION: The pressure of the atmosphere remains the same in both the conditions =ρg*(0.76). But in the upward accelerating elevator the pressure of the mercury column =ρ(g+a)h, since these two are equal so h = (0.76){g/(g+a)}; clearly h<0.76 m i.e. h<76 cm.

A barometer kept in an elevator reads 76cm when it is at rest. If the elevator goes up with increasing speed, the reading will be(a) zero (b) 76cm (c) < 76cm (d) > 76cm.

Answer»

The correct answer is(c) < 76 cm

EXPLANATION:

The pressure of the atmosphere remains the same in both the conditions =ρg*(0.76). But in the upward accelerating elevator the pressure of the mercury column =ρ(g+a)h, since these two are equal so h = (0.76){g/(g+a)}; clearly h<0.76 m i.e. h<76 cm.

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A barometer kept in an elevator reads 76cm when it is at rest. If the elevator goes up with increasing speed, the reading will be(a) zero (b) 76cm (c) &lt; 76cm (d) &gt; 76cm.

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A barometer kept in an elevator reads 76cm when it is at rest. If the elevator goes up with increasing speed, the reading will be(a) zero (b) 76cm (c) < 76cm (d) > 76cm.