physics

A real image three times the size of an object is formed 24cm from a converging mirror. What is the focal length of the mirror?

A. 16cm B. 6cm C. 8cm D. 12cm Correct Answer: Option B - 6cm Explanation For a real image 3…

4 years ago

A thin converging lens has a power of 4.0 diopters determined its focal length.

A. 2.50m B. 0.03m C. 5.00m D. 0.25m Correct Answer: Option D - 0.25m Explanation The power of a lens…

4 years ago

The sharpness of the boundary of the shadow of an object is determined by the?

A. intensity of light striking the object B. rays of light passing through the object C. nature of the object…

4 years ago

Marching soldiers crossing a suspension bridge are usually advised to break their steps to avoid damaging the bridge owing to?

A. oscillation B. resonance C. swinging D. vibration Correct Answer: Option B - resonance Explanation Marching soldiers crossing a suspension…

4 years ago

An engine of a car of power 80 kW moves on a rough road with a velocity of 32 ms−¹. The forces required to bring it to rest is

A. 2.56 x 106N B. 2.50 x 106N C. 2.80 x 103N D. 2.50 x 103N Correct Answer: Option D…

4 years ago

A mirror of weight 75N is hung by a cord from a hook on the wall. If the cord makes an angle of 30o with horizontal; the tension in the cord is?

A. 100N B. 1500N C. 250N D. 150N Correct Answer: Option D - 150N Explanation For vertical equilibrium, we have…

4 years ago

A radioactive substance has a half-life of 20 days what fraction the original radiation nuclei will remain after 80 days?

A. 1/32 B. 1/16 C. 1/ 8 D. 1/4 Correct Answer: Option B - 1/16 Explanation 80 days = 4…

4 years ago

The instrument that measures both A.C and D.C is?

A. a current balance B. a moving current ammeter C. a moving iron ammeter D. an inverter Correct Answer: Option…

4 years ago