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No atmospheric pressure on the surface of moon
Nchoga answered the question on December 12, 2018 at 11:41
- State the reason why the speed of the water at the narrow section of a river is higher than at the wider section(Solved)
State the reason why the speed of the water at the narrow section of a river is higher than at the wider section.
Date posted: November 29, 2018. Answers (1)
- Two vertical opposite forces act on a metre rule at the 10cm and 60cm mark respectively. If each of the forces has a magnitude of 2.4N.calculate...(Solved)
Two vertical opposite forces act on a metre rule at the 10 cm and 60 cm mark respectively.if each of the forces has a magnitude of 2.4N. Calculate their moments on the metre rule about the 30 cm mark.
Date posted: November 13, 2018. Answers (1)
- Explain the applications of junction diodes(Solved)
Explain the applications of junction diodes.
Date posted: October 18, 2018. Answers (1)
- Explain the occurrence of forward bias of a p-n junction and reverse bias of a p-n junction(Solved)
Explain the occurrence of forward bias of a p-n junction and reverse bias of a p-n junction.
Date posted: October 18, 2018. Answers (1)
- What are junction diodes?(Solved)
What are junction diodes?
Date posted: October 18, 2018. Answers (1)
- What is an intrinsic semiconductor?(Solved)
What is an intrinsic semiconductor?
Date posted: October 18, 2018. Answers (1)
- Define the following terms (i) Conductors (ii) Insulators (iii) Semiconductors (Solved)
Define the following terms (i) Conductors (ii) Insulators (iii) Semiconductors
Date posted: October 18, 2018. Answers (1)
- Hazards of radioactivity and their precautions(Solved)
Hazards of radioactivity and their precautions
Date posted: October 17, 2018. Answers (1)
- A radioactive element has an initial count rate of 2,400 counts per minute on a scaler. The count rate falls to 300 units per minute...(Solved)
A radioactive element has an initial count rate of 2,400 counts per minute on a scaler. The count rate falls to 300 units per minute in 30 hours, (a) Calculate the half-life of the element (b) If the initial number of atoms in another sample of the same element is 6.0 × 1020, how many atoms will have decayed in 50 hours?
Date posted: October 17, 2018. Answers (1)
- The initial number of atoms in a sample is 5.12 × 1020. If the half-life of the sample is 3.0 seconds, determine the number of...(Solved)
The initial number of atoms in a sample is 5.12 × 1020. If the half-life of the sample is 3.0 seconds, determine the number of atoms that will have decayed after six seconds.
Date posted: October 17, 2018. Answers (1)
- An isotope has a half-life of 576 hours. Complete the following table and show how mass varies with time from an initial mass of 1280...(Solved)
An isotope has a half-life of 576 hours. Complete the following table and show how mass varies with time from an initial mass of 1280 g?
Time (hrs)----576--1152--1728---2304
Mass (g)-------640--x------y-----z
Date posted: October 17, 2018. Answers (1)
- The half-life of a sample of a radioactive substance is 98 minutes. How long does it take for the activity of the sample to reduce...(Solved)
The half-life of a sample of a radioactive substance is 98 minutes. How long does it take for the activity of the sample to reduce to 1/16th of the original value?
Date posted: October 17, 2018. Answers (1)
- State the law of radioactive decay(Solved)
State the law of radioactive decay
Date posted: October 17, 2018. Answers (1)
- Explain ways of detecting nuclear radiation(Solved)
Explain ways of detecting nuclear radiation.
Date posted: October 17, 2018. Answers (1)
- Properties of radioactive emissions(Solved)
Properties of radioactive emissions
Date posted: October 17, 2018. Answers (1)
- Sodium has a work function of 2.0 e: Calculate (a) The maximum energy and velocity of the emitted electrons when sodium is Illuminated by...(Solved)
Sodium has a work function of 2.0 e: Calculate
(a) The maximum energy and velocity of the emitted electrons when sodium is Illuminated by a radiation of wavelength 150 nm.
(b) Determine the least frequency of radiation by which electrons are emitted. (Take ‘h’ = 6.626 × 10-34 Js, e = 1.6 × 10-19, c = 3.0 × 108 m/s and mass of electron = 9.1 × 10-31 kg).
Date posted: October 17, 2018. Answers (1)
- The threshold frequency for lithium is 5.5 × 1014 Hz. Calculate the work function for lithium. (Take ‘h’ = 6.626 × 10-34 Js)(Solved)
The threshold frequency for lithium is 5.5 × 1014 Hz. Calculate the work function for lithium. (Take ‘h’ = 6.626 × 10-34 Js)
Date posted: October 17, 2018. Answers (1)
- The work function of tungsten is 4.52 e V. Find the cut-off potential for photoelectrons when a tungsten surface is illuminated with radiation of wavelength...(Solved)
The work function of tungsten is 4.52 e V. Find the cut-off potential for photoelectrons when a tungsten surface is illuminated with radiation of wavelength 2.50 × 10-7 m. (Planck’s constant, h = 6.62 × 10-34 Js).
Date posted: October 17, 2018. Answers (1)
- The cut-off wavelength for a certain material is 3.310 × 10-7 m. What is the cut-off frequency for the material?(Solved)
The cut-off wavelength for a certain material is 3.310 × 10-7 m. What is the cut-off frequency for the material?
Date posted: October 17, 2018. Answers (1)
- What is Einstein’s photoelectric equation?(Solved)
What is Einstein’s photoelectric equation?
Date posted: October 17, 2018. Answers (1)