### Physics Past Questions

56

A radio is operated by eight cells each of e.m.f. 2.0V connected in series. If two of the cells are wrongly connected, the net e.m.f. of the radio is

• A. 8V
• B. 10V
• C. 12V
• D. 16V
JAMB 2000
57
If a charged ion goes through combined electric and magnetic fields, the resultant emergent velocity of the ion is
• A. E/B
• B. EB
• C. B/E
• D. E - B
JAMB 2000
58
A projection lantern is used to give the image of a slide on a screen. If the image is 24 times as large as the slide and the screen is 72.0m from the projecting lens, what is the position of the slide from the lens?
• A. 0.3m
• B. 3.0m
• C. 3.5m
• D. 4.0m
JAMB 2000
59
An electron of charge 1.6 x 10-19C and mass 9.1 x 10-31kg is accelerated between two metal plates with a velocity of 4 x 107ms-1, the potential difference between the plates is
• A. 4.55 x 103V
• B. 4.55 x 102V
• C. 9.10 x 101V
• D. 4.55 x 101V
JAMB 2000
60
A cell of internal resistance 0.01â„¦ can be measured accurately using the
• A. Ohm meter
• B. metre bridge
• C. potentiometer
• D. electroscope
JAMB 2000