physics

An iron rod is moved from the earth to the moon. Which of the following properties of the rod would remain unchanged?

i. mass ii. weight iii. relative density A. i only B. ii only C. iii only D. i and iii…

6 years ago

Electrons passing through crystals are diffracted because they?

A. are repelled by the atoms in the crystal B. are attracted by the atoms in the crystals C. possess…

6 years ago

Production of x-ray tube begins with?

A. photoelectric emission B. collision of electrons C. thermionic emission D. field emission of electrons Correct Answer: Option D D.…

6 years ago

Calculate the reactance of the inductor in the circuit diagram shown above [π=22/7]

A. 132Ω B. 214Ω C. 264Ω D. 269Ω Correct Answer: Option C C. 264Ω Explanation XL=2πfL=2×π×60×0.7=264Ω

6 years ago

In the circuit diagram below. Calculate the energy stored in the inductor at resonance.

A. 0.100J B. 0.050J C. 0.010J D. 0.005J Correct Answer: Option B B. 0.050J

6 years ago

The material used for constructing the core of an electromagnet is?

A. iron B. carbon C. copper D. steel Correct Answer: Option A A. iron

6 years ago

Which of the following statements about magnetic lines of force is not correct?

A. a magnetic line of force is an imaginary line which the north pole of a magnet would describe if…

6 years ago

The Earth’s magnetic equator passes through Jos in Nigeria, At Jos?

A. angle of variation is zero B. magnetic declination is 90o C. angle of dip is zero D. horizontal component…

6 years ago

An electric bulb is rated 60W, 220V. Calculate the resistance of its filament when it is operating normally

A. 296.7Ω B. 400.0Ω C. 512.2Ω D. 806.7Ω Correct Answer: Option D D. 806.7Ω Explanation R = V²/P=220²/60 = 806.7Ω

6 years ago

Three identical lamps each power 100W are connected in parallel across a potential difference of 250V. Calculate the current in the circuit

A. 7.5A B. 2.5A C. 1.2A D. 0.8A Correct Answer: Option C C. 1.2A Explanation P = I/V I =…

6 years ago