Question 4391:

• NECO 2001

The wavelength of a stationary wave is 24.0cm. What is the distance between a node and the next antinodes?

A. 6.0cm
B. 12.0cm
C. 18.0cm
D. 24.0cm
E. 48.0cm

Question 4392:

• NECO 2001

How much heat is required to convert 5.0g of ice at 0 ° C to water at the boiling point? (Specific latent heat of ice = 336Jg^-1 specific heat capacity of water = 4.2Jg^-1K^-1)

A. 420 J
B. 1680 J
C. 1701 J
D. 2100 J
E. 3780 J

Question 4393:

• NECO 2001

What gives rise to the line spectra observed in atoms?

A. Change of an electron from a higher to a lower energy level in the atom
B. Disturbed protons in the nucleus
C. Excitation of an electron in the atom
D. Kinetic energy of a moving atom
E. Potential energy of an electron inside an atom

Question 4394:

• NECO 2001

A lead-acid accumulator is used in preference to a dry battery in a car because ____________

A. A dry battery cannot supply the necessary high voltage
B. A dry battery would not operate on a cold frosty morning
C. The accumulator can give a bigger current and can be recharged
D. The accumulator can supply a.c
E. The chemicals used in a dry battery constitute a fire hazard.

Question 4395:

• NECO 2001

A metal has a work function of 3.0 eV. What is the threshold frequency of the metal when electrons are just liberated from the metal.(1 eV = 1.6 × 10-19J; h = 6.6 × 10-34Js)

A. 4.8 × 10^-19Hz
B. 9.3 × 10^-7Hz
C. 4.8 × 10¹⁴Hz
D. 7.3 × 10¹⁴Hz
E. 9.3 × 10¹⁴Hz