Physics 2000 Neco Past Questions and Answers

Question 21 :

• NECO 2000

An electric bell operated within an evacuated bell jar enables us to infer correctly that

A. Light waves require a medium for transmission
B. Sound waves do not require a medium for transmission
C. Light waves do not require a medium for transmission but sound waves do
D. Light waves travel much faster than sound waves
E. Light waves and sound waves travel at the same speed

Question 22 :

• NECO 2000

A boy ran a distance of 200m in 24s. His average speed was 8.3ms^-1. Which of the following is correct about the units in which the statements above are expressed?

A. All the units are fundamental.
B. All the units are derived
C. All the units except one are S.I units
D. Two of the units are fundamental and one derived.
E. None of the units is S.I units.

Question 23 :

• NECO 2000

A particle of charge q and mass m moving with a velocity v enters a uniform magnetic field B in the direction of the field. The force on the particle is ____________

A. Bqv
B. Bq\(\frac{v}{m}\)
C. Bqvm
D. Mv\(\frac{B}{q}\)
E. \(\frac{mv}{Bq}\)

Question 24 :

• NECO 2000

The helium isotope \(^3_2He\)

A. Has three pro tons and two neutrons
B. Has two protons and one neutron
C. Has two protons and three neutrons
D. Has one proton and two neutrons
E. Cannot exist because it has the same mass number as tritium

Question 25 :

• NECO 2000

When a metal is heated to a high temperature, electrons are emitted from its surface. The process is known as ____________

A. Photoelectric effect
B. Thermionic emission
C. Field emission
D. Secondary emission
E. Radioactive emission