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Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

2,896.

When 100g of liquids L1 at 78°C was mixed with Xg of liquid L2 at 50°C, the final temperature was 66°C. Given that the specific heat capacity of L2is half that of L1, find x

A.

50g

B.

100g

C.

150g

D.

200g

Correct answer is C

Heat lost by L1 = heat gained by L2

cL1 = 2cL2

100 x 2cL2 x (78 - 66)

= xg x cL2 x (66 - 50)

xg = 150g

2,897.

A Motor Tyre is inflated to pressure of 2.0 x 105Nm-2 when the temperature of air is 27oC. What will be the pressure in it at 87oC assuming that the volume of the Tyre does not change?

A.

2.6 x 105Nm-2

B.

2.4 x 105Nm-2

C.

2.2 x 105Nm-2

D.

1.3 x 105Nm-2

Correct answer is B

p1T1 = p2T2

2×10527+273 = p287+273

P2 = 2.4 x 105Nm-2

2,898.

The melting point of naphthalene is 78oC. What is this temperature in kelvin

A.

100k

B.

351k

C.

378k

D.

444k

Correct answer is B

T = 78 + 273

= 351k

2,899.

If a solid X floats in liquids P of relative density 2.0 and in liquid Q of relative density 1.5, it can be inferred that the

A.

weight of P displaced is greater than that of Q

B.

weight of P displaced is less than that of Q

C.

volume of P displaced is greater than that of Q

D.

volume of P displaced is less than that of Q

Correct answer is A

R.d α weight of liquid displaced

R.d of PR.d of Q = weight of p displacedweight of Q displaced

21.5 = weight of p displacedweight of Q displaced

2,900.

The mass of a specific gravity bottle is 15.2g when it is empty. it is 24.8g when filled with kerosene and 27.2g when filled with distilled water. Calculate the relative density of kerosene

A.

1.25

B.

1.10

C.

0.90

D.

0.80

Correct answer is D

Masses of kerosene = 24.8 - 15.2

= 9.6

mass of H2O = 27.2 - 15.2

= 12

R.d = 9.612 = 0.8