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- In an X-ray tube, the accelerating voltage is 100KV.(Solved)
In an X-ray tube, the accelerating voltage is 100KV.
i) Calculate the kinetic energy of the electrons arriving at the target (take e = 1.6 x 10-19C)
ii) If 0.5% of the kinetic energy is converted to X-rays, determine the minimum wavelength of the emitted X-rays (take h = 6.63 x 10-34Js and C = 3.0 x 108m/s)
Date posted: September 30, 2019. Answers (1)
- You are provided with the following apparatus used for studying charging of a capacitor. An uncharged capacitor, voltmeter, milliameter, 6V battery, connecting wires, a switch...(Solved)
You are provided with the following apparatus used for studying charging of a capacitor. An uncharged capacitor, voltmeter, milliameter, 6V battery, connecting wires, a switch and a load resistor R.
i) Draw a circuit diagram that can be used to charge the capacitor.
ii) Use the circuit diagram drawn above to explain how the capacitor gets charged.
iii) State the purpose of resistor R.
Date posted: September 30, 2019. Answers (1)
- The distance of separation between the plates of a certain capacitor is reduced. State how this affects the capacitance of a capacitor.(Solved)
The distance of separation between the plates of a certain capacitor is reduced. State how this affects the capacitance of a capacitor.
Date posted: September 30, 2019. Answers (1)
- A house has three rooms each with two 240V, 60W bulbs. If the bulbs are switched on from 7.00p.m to 10.00pm daily.(Solved)
A house has three rooms each with two 240V, 60W bulbs. If the bulbs are switched on from 7.00p.m to 10.00pm daily.
i) Calculate the power consumed per day in kilowatt-hours.
ii) Find the cost per week for lighting these rooms at sh.6.30 per kilowatt hour.
Date posted: September 30, 2019. Answers (1)
- Uranium -234 undergoes a radioactive decay represented by the equation shown below.(Solved)
Uranium -234 undergoes a radioactive decay represented by the equation shown below.
Find the value of a and b
Date posted: September 30, 2019. Answers (1)
- Given that the wavelength of a certain electromagnetic wave is 7500cm, determine its frequency. (Take the speed of light in a vacuum as 3.0 x...(Solved)
Given that the wavelength of a certain electromagnetic wave is 7500cm, determine its frequency. (Take the speed of light in a vacuum as 3.0 x 108m/s)
Date posted: September 30, 2019. Answers (1)
- The figure below shows an image I formed by an object placed in front of a convex mirror. C and F are the centre of...(Solved)
The figure below shows an image I formed by an object placed in front of a convex mirror. C and F are the centre of curvature and principal focus of the mirror respectively. Using appropriate rays locate the object position.
Date posted: September 30, 2019. Answers (1)
- The figure below shows part of an electric circuit. The charge stored in the 9µF capacitor is 1.4 micro coulombs(Solved)
The figure below shows part of an electric circuit. The charge stored in the 9μF capacitor is 1.4 micro coulombs
Determine the p.d across the 5μF capacitor.
Date posted: September 30, 2019. Answers (1)
- The figure below shows water waves travelling from region A through B to C in a ripple tank.(Solved)
The figure below shows water waves travelling from region A through B to C in a ripple tank.
On the same diagram, complete the figure to show incident waves at region A and after crossing the boundary to C.
Date posted: September 30, 2019. Answers (1)
- A coin is placed at the bottom of a beaker filled with water to a height of 2.4cm as shown in the figure below. Given...(Solved)
A coin is placed at the bottom of a beaker filled with water to a height of 2.4cm as shown in the figure below. Given that the refractive index of water is 1.33, determine the apparent depth of the coin.
Date posted: September 30, 2019. Answers (1)
- A certain car battery is rated 30Ah. Determine the amount of current it can supply in 10 minutes.(Solved)
A certain car battery is rated 30Ah. Determine the amount of current it can supply in 10 minutes.
Date posted: September 30, 2019. Answers (1)
- A soft iron bar AB is placed in a magnetic field of a horse shoe magnet as shown below.(Solved)
A soft iron bar AB is placed in a magnetic field of a horse shoe magnet as shown below.
What are the polarities of A and B.
Date posted: September 30, 2019. Answers (1)
- State two differences between sound waves and microwaves.(Solved)
State two differences between sound waves and microwaves.
Date posted: September 30, 2019. Answers (1)
- A current carrying wire is placed above a compass needle as shown in the figure below.If the current flows in the direction A to B,...(Solved)
A current carrying wire is placed above a compass needle as shown in the figure below.If the current flows in the direction A to B, show in the diagram the deflection of the compass needle.
Date posted: September 30, 2019. Answers (1)
- The figure below shows a bulb hydrometer.(Solved)
The figure below shows a bulb hydrometer.
i) State the principle in the hydrometer.
ii) Explain why the hydrometer has a weighted bulb and narrow stem.
Date posted: September 30, 2019. Answers (1)
- Give a reason why when a passenger jumps from a floating boat, the boat moves backwards.(Solved)
Give a reason why when a passenger jumps from a floating boat, the boat moves backwards.
Date posted: September 30, 2019. Answers (1)
- A trailer of mass 30 tonnes travelling at a velocity of 72km/h runs onto a stationary bus of mass 10 tonnes.The impact takes 0.5 seconds...(Solved)
A trailer of mass 30 tonnes travelling at a velocity of 72km/h runs onto a stationary bus of mass 10 tonnes.The impact takes 0.5 seconds before the two vehicles move off together at a constant velocity for 15 seconds. Determine:
i) The common velocity.
ii) The distance moved after the impact.
iii) The impulsive force on the trailer on impact.
Date posted: September 30, 2019. Answers (1)
- The figure below shows a trolley moving on a circular rail with a vertical plane, given that the mass of the trolley is 250g and...(Solved)
The figure below shows a trolley moving on a circular rail with a vertical plane, given that the mass of the trolley is 250g and the radius of the rail is 1.6m.
i) Determine the minimum velocity at which trolley passes point X.
ii) Find the angular velocity at point Z.
iii) The force exerted on the rail at this point.
Date posted: September 30, 2019. Answers (1)
- What does study of thermodynamics entails?(Solved)
What does study of thermodynamics entails?
Date posted: September 30, 2019. Answers (1)
- A tall building has two barometers, one at the ground floor reading 750mmHg and the other at the top reading 748mmHg. Determine the height of...(Solved)
A tall building has two barometers, one at the ground floor reading 750mmHg and the other at the top reading 748mmHg. Determine the height of the building.
Date posted: September 30, 2019. Answers (1)