physics

Which of the following statements is true of ultraviolet radiation? It

A. supports the sensation of hearing B. does not cause the emission of electrons from metals C. is an electromagnetic…

6 years ago

Which of the following statements is not true of the isotopes of an element? They

A. are atoms of the same element B. have the same chemical properties C. have the same atomic number D.…

6 years ago

Which of the following statements about an electromagnet is correct?

A. it is a temporary magnet B. its strength depends on the current C. its strength depends on the number…

6 years ago

One difference between reactance and resistance in an alternating current circuit is?

A. resistance is larger than reactance B. energy is not dissipated in a reactance C. energy is stored in resistance…

6 years ago

The maximum power dissipated by a 100Ω resistor in a circuit is 4W. Calculate the voltage across the resistor.

A. 10V B. 20V C. 25V D. 400V Correct Answer: Option B B. 20V Explanation V²=PR=V=√4x100 = 20V

6 years ago

A lamp is rated 240V 60W, calculate the resistance of its filament.

A. 240Ω B. 360Ω C. 960Ω D. 1440Ω Correct Answer: Option C C. 960Ω Explanation R = V²/P=240²/60 =960Ω

6 years ago

A current of 10A passes through a conductor for 10s, calculate the charge flowing through the conductor.

A. 100.0C B. 10.0C C. 1.0C D. 0.1C Correct Answer: Option A A. 100.0C Explanation Q = it = 10…

6 years ago

Which of the following factors does not affect the electric resistance of a wire?

A. length B. mass C. temperature D. cross-sectional area Correct Answer: Option B B. mass

6 years ago

A positively charged glass rod is placed near the cap of a positive charged electroscope. The divergence of the leaf is observed to

A. decrease B. increase C. remain the same D. increase and collapse immediately Correct Answer: Option B B. increase

6 years ago