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i) To be easily ionized by the radiation.
ii) Acts as a quenching agent
Absorbing kinetic energy of the positive ions
Kavungya answered the question on October 17, 2019 at 11:32
- Sodium has work function of 2.42eV. Calculate its threshold frequency.
(Take the plank’s constant to be 6.6 x 10-34 J)
(Solved)
Sodium has work function of 2.42eV. Calculate its threshold frequency.
(Take the plank’s constant to be 6.6 x 10-34 J)
Date posted: October 17, 2019. Answers (1)
- i)Sketch on the axis below a graph of the e.m.f generated against the angle as the coil rotates from 00 to 900 and from 900...(Solved)
i)Sketch on the axis below a graph of the e.m.f generated against the angle as the coil rotates from 00 to 900 and from 900 to 1800.
ii)Give reasons for the changes in the e.m.f as the coil rotates from 00 to 1800.
Date posted: October 17, 2019. Answers (1)
- How is flux leakage minimized?(Solved)
How is flux leakage minimized?
Date posted: October 17, 2019. Answers (1)
- Define flux leakage as used in transformers.(Solved)
Define flux leakage as used in transformers.
Date posted: October 17, 2019. Answers (1)
- The diagram below is a circuit with 2 bulbs and components D.
State and explain which of the lamps L1 and L2 would light when the...(Solved)
The diagram below is a circuit with 2 bulbs and components D.
State and explain which of the lamps L1 and L2 would light when the switch is closed.
Date posted: October 17, 2019. Answers (1)
- A tube of length 36cm is closed at one end. It is at resonance with a turning fork of frequency 256Hz sounded above the open...(Solved)
A tube of length 36cm is closed at one end. It is at resonance with a turning fork of frequency 256Hz sounded above the open end. Given that the velocity of sound in air is 334m/s.
Determine:
i)The wavelength of the wave generated by the turning fork.
ii)The end correction of the tube.
Date posted: October 17, 2019. Answers (1)
- State two conditions necessary for production of constructive interference. (Solved)
State two conditions necessary for production of constructive interference.
Date posted: October 17, 2019. Answers (1)
- The figure below shows plane waves in a ripple tank. The water is deeper in section A and C then in section B.
Draw the waves...(Solved)
The figure below shows plane waves in a ripple tank. The water is deeper in section A and C then in section B.
Draw the waves after passing section B.
Date posted: October 17, 2019. Answers (1)
- A student set up a circuit using three identical bulbs A,B and C each rated at 6V, 1.0A as shown below
i)Determine the resistance of one...(Solved)
A student set up a circuit using three identical bulbs A,B and C each rated at 6V, 1.0A as shown below
i)Determine the resistance of one of the bulbs when operating normally.
ii)Calculate the effective resistance of the three bulbs.
iii)Draw a circuit diagram showing the three bulbs A, B and C connected in such a way that they would all light at normal brightness.
Date posted: October 17, 2019. Answers (1)
- State the type of electromagnetic spectrum emitted by warm objects.(Solved)
State the type of electromagnetic spectrum emitted by warm objects.
Date posted: October 17, 2019. Answers (1)
- The figure below shows a ray of light travelling through water, whose refractive index is 1.33.
Determine the refractive index of glass. (Solved)
The figure below shows a ray of light travelling through water, whose refractive index is 1.33.
Determine the refractive index of glass.
Date posted: October 17, 2019. Answers (1)
- The graphs in the figure below represent the same wave.
Determine the velocity of the wave.(Solved)
The graphs in the figure below represent the same wave.
Determine the velocity of the wave.
Date posted: October 17, 2019. Answers (1)
- The figure below shows the path of a ray of light after striking two mirrors XY and YZ at an angle.
Determine the angle between the...(Solved)
The figure below shows the path of a ray of light after striking two mirrors XY and YZ at an angle.
Determine the angle between the two mirrors
Date posted: October 17, 2019. Answers (1)
- An object 10cm high is placed 30cm in front of a concave mirror. The image is 45cm in front of the mirror. Find its magnification...(Solved)
An object 10cm high is placed 30cm in front of a concave mirror. The image is 45cm in front of the mirror. Find its magnification and size of the image.
Date posted: October 17, 2019. Answers (1)
- In an attempt to make a magnet, a student used the double stroke method as shown below.
State the polarities at the ends A and B(Solved)
In an attempt to make a magnet, a student used the double stroke method as shown below.
State the polarities at the ends A and B
Date posted: October 17, 2019. Answers (1)
- The figure below shows a metallic sphere (A) suspended by a cotton thread. A negatively charged rod (B) is brought near the sphere. Explain other...(Solved)
The figure below shows a metallic sphere (A) suspended by a cotton thread. A negatively charged rod (B) is brought near the sphere. Explain other three steps for charging sphere A positive.
Date posted: October 17, 2019. Answers (1)
- 500g of water at 200C is mixed with 200g of water at 550C. Find the final temperature of the mixture. (Solved)
500g of water at 200C is mixed with 200g of water at 550C. Find the final temperature of the mixture.
Date posted: October 17, 2019. Answers (1)
- A car moving initially at 10m/s decelerates at 2.5m/s2
Determine:
i)I) Its velocity after 1.5seconds.
II)The distance travelled in 1.5 seconds.
III)The time taken for the car to stop.
ii)Sketch...(Solved)
A car moving initially at 10m/s decelerates at 2.5m/s2
Determine:
i)I) Its velocity after 1.5seconds.
II)The distance travelled in 1.5 seconds.
III)The time taken for the car to stop.
ii)Sketch the velocity – time graph for the motion of the car up to the time the car stopped.
iii)From the graph determine the distance the car travelled before stopping.
Date posted: October 17, 2019. Answers (1)
- The diagram below shows a six’s maximum/ minimum thermometer.
a)What is the thermometric liquid in this thermometer?
b)Why is it necessary for the vapour in bulb B...(Solved)
The diagram below shows a six’s maximum/ minimum thermometer.
)What is the thermometric liquid in this thermometer?
b)Why is it necessary for the vapour in bulb B to be saturated?
c)Explain how the thermometer indicates maximum and minimum temperature.
d)Indicate on the diagram the two points where the reading of the temperature shown by the
thermometer can be made.
Date posted: October 17, 2019. Answers (1)
- Use the figure below to answer the questions that follow
i)What pressure is acting on point A?
ii)What is the value of pressure difference in the...(Solved)
Use the figure below to answer the questions that follow
i)What pressure is acting on point A?
ii)What is the value of pressure difference in the instrument reading?
iii)If the atmospheric pressure is 760mm of mercury, what is the value of gas pressure?
Date posted: October 17, 2019. Answers (1)