Question 126:

• JAMB 1980

A tugboat is travelling from Asaba to Onitsha across the River Niger with a resultant velocity of 20 knots. If the river flows at 12 knots, the direction of motion of the boat relative to the direction of water flow is

A. 36.87^oC
B. 53.13^oC
C. 90^oC
D. 136^oC
E. 143.13^oC

Question 127:

• JAMB 1980

A milliameter of resistance 5\(\Omega\) and full scale deflection of 5m A is to used to measure a potential difference of 50 V. The resistance of the multiplier should be

A. 95\(\Omega\)
B. 110\(\Omega\)
C. 595\(\Omega\)
D. 995\(\Omega\)
E. 1005\(\Omega\)

Question 128:

• JAMB 1980

An object of mass m and volume v, is totally immersed in a liquid of density p. The tension of a string holding it is

A. Mg
B. (m + pv)g
C. (m - pv)g
D. Pvg
E. [M/m-pv]g

Question 129:

• JAMB 1980

The relative densities of zinc, brass, copper, gold and silver are respectively 7.1, 8.5, 8.9, 19.3, 10.5. A metal ornament which weighs 0.425kg and can displace 50 x 10^-6m³m of water is made of

A. Zinc
B. Brass
C. Copper
D. Gold
E. Silver

Question 130:

• JAMB 1980

Heat is supplied to a block of ice 0^o until half of it has melted. Which of the following statements is true?

A. The temperature rises and the ice exoands
B. The temperature remains constant and the volume of ice decreases
C. The ice gives out heat as it melts
D. The mass remains constant and the temperature increases
E. The mass decreases because some heat is lost to the atmosphere