physics

Which of the following instruments produces sound by the vibration of air column?

A. Piano B. Guitar C. Flute D. Hand bell E. Talking drum Correct Answer: Option C - Flute

5 years ago

A converging lens of focal length 5cm forms a virtual image which is 10cm from the lens. How far from the lens is the object?

A. 2.0cm B. 3.3cm C. 5.0cm D. 10.0cm E. 15.0cm Correct Answer: Option B - 3.3cm Explanation f = uv/(u+v)…

5 years ago

The refractive index of a medium relative to air is 1.8. Calculate the critical angle for the medium to the nearest degree.

A. 18° B. 34° C. 45° D. 68° E. 90° Correct Answer: Option B - 34°

5 years ago

When a ray of light is incident normally on an air- glass interface, its angle of refraction is?

A. 0° B. 42° C. 45° D. 60° E. 90° Correct Answer: Option A - 0°

5 years ago

The inside of a vacuum flask is usually coated with silver to reduce heat lost by?

A. convection B. conduction C. radiation D. absorption E. evaporation Correct Answer: Option C - radiation

5 years ago

The heating element in an electric kettle is usually located near the bottom of the kettle because?

A. water is a good conductor of heat B. heat can be more quickly radiated to all parts of the…

5 years ago

When a ray of light is incident normally on an air-glass interface, its angle of refraction is?

A. 0° B. 42° C. 45° D. 60° E. 90° Correct Answer: Option A - 0°

5 years ago

A boy walks away from a plane mirror at a speed of 3 ms-1 in a direction normal to the surface of the mirror. At what speed is his image approaching him?

A. 89.0ms-1 B. 6.0ms-1 C. 4.5ms-1 D. 1.5ms-1 E. 0.0ms-1 Correct Answer: Option B - 6.0ms-1 Explanation Velocity of image…

5 years ago

A ray of light strikes a plane mirror at a glancing angle of 50°. Calculate the angle between the incident and reflected rays?

A. 20° B. 40° C. 50° D. 80° E. 100° Correct Answer: Option D - 80°

5 years ago

In which of the following media would sound waves travel fastest?

A. Kerosine B. Alcohol C. Water D. lron E. Air Correct Answer: Option D - lron

5 years ago
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