Post Utme Physics Past Questions and Answers

Question 936:

Which of the following is not a reason for using soft iron in making core of a transformer?

A. Retains its magnetism for a long time
B. Is easily magnetized
C. Reduces energy loss due to hysteresis
D. Is easily demagnetized
E. None of the above

Question 937:

The main function of the mouth piece of a telephone is that; it converts sound energy to _____________

A. Mechanical energy
B. Hectrical energy
C. Chemical energy
D. Thermal energy

Question 938:

The efficiency of a machine is always less than 100% because the _____________

A. Velocity ration is always greater than the mechanical advantage
B. Work output is always greater than then work input
C. Effort applied is always greater than the load lifted
D. Load lifted is always greater than the effort applied

Question 939:

The height at which atmosphere ceases to exist is about 80km. if the atmospheric pressure on the ground level is 760mmbHg, the pressure at a height of 20km above the ground level is _____________

A. 380 mmHg
B. 190 mmHg
C. 750 mmHg
D. 480 mmHg

Question 940:

A stone of mass 1kg is dropped from a height of 10m above the ground and falls freely under gravity. Its kinetic energy Sm above the ground is the equal to _____________

A. Its kinetic energy on the ground.
B. Half its initial potential
C. Initial potential energy
D. Twice its initial potential energy