physics

The number of protons in an element increased by one after a radioactive decay. The element must have decay by emitting?

A. a beta particle B. an alpha particle C. a gamma ray D. a neutron Correct Answer: Option A A.…

6 years ago

If a gas is excited by high voltage to produce discharge and the light is examined in a spectrometer?

A. an explosion is observed B. the rainbow colours are seen C. an emission spectrum is observed D. dark lines…

6 years ago

Which of the following electromagnetic wave can be detected by its heating effect?

A. ultraviolet radiation B. x-rays C. gamma rays D. infrared radiation Correct Answer: Option D D. infrared radiation

6 years ago

Five 80-W and three 100W are run for 8 hours. If the cost of energy is N5.00 per unit, calculate the cost of running the lamp. [1 unit = 1 kWh]

A. N280.00 B. N28.00 C. N7.20 D. N1.44 Correct Answer: Option B B. N28.00 Explanation P = (80 x 5…

6 years ago

A bulb marked 240V, 40W is used for 30 minutes. Calculate the heat generated?

A. 320J B. 400J C. 10800J D. 72000J Correct Answer: Option D D. 72000J Explanation W = P x t…

6 years ago

Which of the following operations does not represent an action of a force field?

A. falling of mango fruit from the tree B. picking of nails using a bar magnet C. repulsion of two…

6 years ago

Which of the following components is used for storing electric charges?

A. inductor B. resistor C. capacitor D. electrometer Correct Answer: Option C C. capacitor

6 years ago

Which of the following statements is correct about resonance? Resonance occurs when a body?

A. vibrates with its natural frequency B. is forced to vibrate on its own natural frequency by another body at…

6 years ago

When an object is placed at the centre of curvature of a concave mirror, its image is formed at?

A. the focus B. infinity C. the centre of curvature D. a distance twice the radius of curvature Correct Answer:…

6 years ago

In which of the following piece of apparatus is the radius of curvature equal to twice the focal length?

A. converging lens B. diverging lens C. converging mirror D. parabolic mirror Correct Answer: Option C C. converging mirror

6 years ago