Question 691:

• JAMB 1992

The speed of light in air is 3 x 10⁸ms^-1. What is the speed in glass with a refractive index of 1.50?

A. 1.5 x 10⁸ms^-1
B. 3.0 x 10⁸ms^-1
C. 2.0 x 10⁸ms^-1
D. 6.0 x 10⁸ms^-1

Question 692:

• JAMB 1992

If the refractive index of a medium in air is 2.0, what is the critical angle for this medium?

A. 30^o
B. 42^o
C. 45^o
D. 50^o

Question 693:

• JAMB 1992

Which of the following arrangements of the components of electromagnetic spectrum is in ascending order of wavelengths?

A. Gamma rays, ultraviolet rays, X- rays, infra - red rays
B. Gamma rays, X-rays, ultraviolet rays, infra-red rays
C. Infra-red rays, ultraviolet rays, X-rays, gamma rays
D. Gamma rays, ultraviolet rays, infra-red rays, X-rays

Question 694:

• JAMB 1992

The angle between the direction of the earth's magnetic field and the horizontal is called the

A. Angle of deviation
B. Magnetic declination
C. Magnetic meridian
D. Angle of dip

Question 695:

• JAMB 1992

Calculate the force acting on an electron of charge 1.6 x 10^-19C placed in an electric field of intensity 10⁸Vm^-1

A. 1.6 x 10^-11N
B. 1.6 x 10^-14N
C. 1.6 x 10^-16N
D. 1.0 x 10^-16N