Jamb Physics 1994 Past Questions and Answers

Question 26:

• JAMB 1994

To produce a parallel beam of light from a concave mirror, the distance at a which the lamp should be placed from the mirror is equal to

A. The focal length
B. Two times the focal length
C. The distance of the image
D. Two times the radius of curvature

Question 27:

• JAMB 1994

Light of frequency 6.0 x 10¹⁴ Hz travelling in air is transmitted through glass or refractive index 1.5. Calculate the frequency of the light in the glass

A. 4.0 x 10¹⁴Hz
B. 6.0 x 10¹⁴Hz
C. 7.5 x 10¹⁴Hz
D. 9.0 x 10¹⁴Hz

Question 28:

• JAMB 1994

An object is placed in front of a converging lens of a focal length 20cm. The image is virtual and has a magnification of 2. What is the distance of the object from the lens?

A. 5cm
B. 10cm
C. 30cm
D. 40cm

Question 29:

• JAMB 1994

An object is placed directly below a glass block of thickness 3.0cm. Calculate the lateral displacement of the object if the refractive index of the glass is 1.5.

A. 1.0cm
B. 1.5cm
C. 2.0cm
D. 2.5cm

Question 30:

• JAMB 1994

In a projection lantern of focal length f, the object distance u, is such that

A. U > 2f > f
B. U < f < 2f
C. U = f < 2f
D. F < u < 2f