Physics Past Questions and Answers

On which of the following does the operation of a moving coil ammeter depend? i. Electromagnetic induction ii. Force on a carrying-current conductor iii. Magnetic effect of an electric current

A I only
B Ii only
C Iii only
D Ii and iii only
E I,ii and iii

Question 367:

Which of the following statements is NOT correct?

A A galvanometer can be converted to an ammeter with a different range by connecting a high resistance in series
B An electric current always produces a magnetic field
C Maxwell's screw rule states that if a corkscrew moves inthe direction of the current, the hand turns in the direction of the lines of force
D Electromagnets are used in electric bells and telephone recievers
E The lines of force round a straight current carrying conductor are circular

Question 368:

A transformer has a primary coil with 500 turns and a secondary coil with 2500 turns. When the voltage input to the primary coil is 120V, the output is

A 6000V
B 600V
C 240V
D 60V
E 24V

Question 369:

Which of the following statements about electrolysis is NOT correct?

A The substances in solution in the electrolyte become ionized
B Ions are electrically charged and are attracted towards electrodes when a potential difference is applied
C Ions may be discharged at the electrodes, forming bubbles or deposits
D The mass deposited depends upon the length of time for which current flows
E The mass of gas set free or metal deposited is proportional to the square of the current

Question 370:

Which of the following statements is NOT correct?

A The average range of distinct vision for a normal eye is from the far distance (infinity) up to about 25cm in front of the eye
B Longsighted people have difficulty in making the eye lense sufficiently powerful to focus on nearby objects
C Shortsighted people cannot accommodate distant objects
D Longsighted people need diverging spectacle lenses
E A person with long sight has his eye-ball too short and the image of an object is therefore formed behind the retina