JAMB Physics Past Questions & Answers - Page 159

791.

If a projectile has maximum range of 36m, find the speed of projection (Take g = 9.8m/s2)

A.

19m/s

B.

2m/s

C.

4m/s2

D.

7m/s2

Correct answer is A

No explanation has been provided for this answer.

792.

Neutron were discovered by

A.

J.J. Thompson

B.

James Chadwick

C.

Michael faraday

D.

Dalton

Correct answer is B

Neutron were discovered by James Chadwick in 1931

793.

The two liquids which are often used in thermometer on experiment basic is known as

A.

Mercury only

B.

Alcohol and Water

C.

Mercury and Alcohol

D.

Alcohol only

Correct answer is C

Mercury and alcohol are often used in THERMOMETER

Note:Water is never allowed to be used in thermometer because, it doesn’t expand uniformly

794.

Transformers are designed so that energy losses are reduced to a minimum. This is achieved through which of these process?

I. Using a soft iron ore
II. Laminating the iron core to reduce energy loses due to eddy current
III. Designing an efficient iron core

A.

I & II only

B.

II only

C.

I, II, & III only

D.

III only

Correct answer is C

Fig (I) (II) (III) are they in which a transformer was designed to reduce an energy loses by reducing through this collective designed or efforts

795.

Which of the following will increase the boiling point of water?

I. Taking it to a high altitude
II. Dissolving a salt into it
III. Heating it in a sealed flask
IV. Increasing the rate of heat supply

.

A.

I only

B.

III & IV only

C.

II & III only

D.

II only

Correct answer is C

The simplest way to change the boiling point of a liquid is to change the surrounding pressure. (a) Using a closed system to artificially increase that pressure will raise the boiling point of a liquid. (b)  Boiling point is dependent upon the strength of the bonds between its molecules. For this reason, adding a solute to the liquid will create stronger bonds between molecules, raising the solution’s boiling point without increasing pressure.