Question 426:

• JAMB 1986

In fig 9 the value of R is

A. 3Ω
B. 4Ω
C. 5Ω
D. 6Ω

Question 427:

• JAMB 1986

if the fig above E is an accumulator with negligible internal resistance. and the EMF 9.0V, The the total current is

A. 0.3A
B. 0.8A
C. 1.0A
D. 1.8A

Question 428:

• JAMB 1986

In fig 6, a ray of light in air strikes a glass plate at an angle of incidence 60 degrees, the reflected ray is observed to be perpendicular to the refracted ray, what is the refractive index of the glass

A. 1.73
B. 1.50
C. 0.87
D. 0.57

Question 429:

• JAMB 1986

In an experiment in which molten naphthalene is allowed to cool, the cooling curve in fig 5 was obtained, the temperature \( 80^{\circ}C \) is known as

A. Cooling temperature
B. Boiling point
C. Melting point
D. Vaporization point

Question 430:

• JAMB 1986

fig 4 represents a block-and-tackle pulley system on which an effort of W newtons supports a load of 120.0N if the efficiency of the system is 40% then the value of W is

A. 28.0N
B. 48.0N
C. 50.0N
D. 288.0N