Jamb Physics Past Questions For Year 1978

Question 46

A temperature 20°C is the same as

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• A. 36^oF
• B. 68^oF
• C. 11.1^oF
• D. 43.1^oF
• E. 25^oF

Question 47

A few grains of table salt were put in a cup of water, kept at constant temperature and left undisturbed. Eventually all the water tasted salty. The action is due to

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• A. convection
• B. osmosis
• C. capillarity
• D. diffusion
• E. conductivity

Question 48

The statements below were made by some students describing what happened during the determination of the melting point of solids.

i. the temperature of the solid was solid until melting started

ii. the temperature of the solid rose until melting started

iii. during melting, the temperature was rising

iv. during melting, the temperature was constant

v. the temperature continued to rise after all the solid had melted

vi. the temperature stopped rising after all the solid had melted. Which of the following gives correct statements in the right order?

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• A. ii, iv, and v
• B. ii, iii and vi
• C. i, iii and vi
• D. i, iii and v
• E. i, iv and v

Question 49

A solid suspended by a piece of string is completely immersed in water. On attempting to lift the solid out of the water, the string breaks when the solid is partly out of the water. This is because

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• A. the tension in the string decreases as the solid is lifted
• B. the mass of the solid has increased
• C. the solid apparently weighs less when completely immersed in water than when partially immersed
• D. part of the solid still in water is exerting more force on the string
• E. the solid is no longer in equilibrium with water