I. All elements emit and absorb characteristic spectra. II. Spectral analysis is an important method of identifying environmental pollutants. III. The chemical composition of stars could be determined using spectral analysis. Which of the statements above are correct?

• A. I, II and III
• B. II and III only
• C. I and III only
• D. I and II only

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

Which of the following statements correctly defines quantitatively the work done by a force? the product of the force and the distance moved

• A. parallel to the line of action of the force from a reference point
• B. perpendicular to the line of action of the force from a reference point
• C. on a line through the reference point
• D. by the object

The time rate of change of momentum is

• A. impulse
• B. force
• C. power
• D. pressure

Find the tension in the two cords shown in the figure above. Neglect the mass of the cords, and assume that the angle is 38° and the mass m is 220 kg

[Take g = 9.8 ms^-2]

• A. \(T_1\) = 2864 N, \(T_2\)= 3612 N
• B. \(T_1\)= 3612 N, \(T_2\) = 2864 N
• C. \(T_1\)= 3502 N, \(T_2\)= 2760 N
• D. \(T_1\) = 2760 N, \(T_2\) = 3502 N

Which of the following units is equivalent to the unit of electric current?

• A. C s\({-1}\)
• B. W
• C. J s\({-1}\)
• D. C

The inner diameter of a test tube can be measured accurately using a?

• A. micrometer screw gauge
• B. pair of dividers
• C. meter rule
• D. pair of vernier calipers

(a) List two types of waves, apart from light, that can be plane polarized.

(b) State two applications of plane polarized light.

Given the inductor of inductance 5mH, 10mH and 20mH connected in series, the effective inductance is

• A) 0.35mH
• B) 3.50mH
• C) 2.90mH
• D) 35.0mH

An object is placed 5 cm from the pole of a concave mirror. if the focal length of the mirror is 10 cm. what is the image distance?

• A) 10 cm in front of the mirror.
• B) 5 cm in front of the mirror
• C) 10 cm behind the mirror
• D) 5 cm behind the mirror