Q.7 The information from one place to another can be transmitted very safely and easily by:
A) Copper wire C) Photodiode
B) Aluminium wire D) Optical fibre
A) Copper wire C) Photodiode
B) Aluminium wire D) Optical fibre
Q.8 The image of an object placed inside the focal length of a convex lens will be largest and clearest when it is at the
A) Less than 25 cm C) Greater than 25 cm
B) Near point D) Infinity
A) Less than 25 cm C) Greater than 25 cm
B) Near point D) Infinity
Q.9 The minimum distance from the eye at which an object can be seen clearly without strain is called:
A) Focal point C) Yield point
B) Near point D) Far point
Q.10 In the diffraction of light around an obstacle, the angle of diffraction is increased then:
A) The wavelength of incident light wave is increased C) The amplitude of the incident light wave is increased
B) The wavelength of incident light wave is decreased D) The amplitude of the incident light wave is decreased
Q.11 An object 15 cm from a lens produces a real image 30 cm from the lens. What is the focal length of the lens?
A) +15 cm C) +10 cm
B) +20 cm D) +25 cm
A) Focal point C) Yield point
B) Near point D) Far point
Q.10 In the diffraction of light around an obstacle, the angle of diffraction is increased then:
A) The wavelength of incident light wave is increased C) The amplitude of the incident light wave is increased
B) The wavelength of incident light wave is decreased D) The amplitude of the incident light wave is decreased
Q.11 An object 15 cm from a lens produces a real image 30 cm from the lens. What is the focal length of the lens?
A) +15 cm C) +10 cm
B) +20 cm D) +25 cm