Get premium membership and access questions with answers, video lessons as well as revision papers.
P = $\frac{V^2}{R}$
R = $\frac{240^2}{75}$
= 768
johnmulu answered the question on February 15, 2017 at 12:49
- An electric bulb with a filament of resistance 480 ohms is connected to a 240 V mains supply. Determine the energy dissipated in 2 minutes(Solved)
An electric bulb with a filament of resistance 480 ohms is connected to a 240 V mains supply. Determine the energy dissipated in 2 minutes
Date posted: February 15, 2017. Answers (1)
- A 60 W bulb is used continuously for 36 hours. Determine the energy consumed. Give your answer in kilowatt hour (kWh)(Solved)
A 60 W bulb is used continuously for 36 hours. Determine the energy consumed. Give your answer in kilowatt hour (kWh)
Date posted: February 15, 2017. Answers (1)
- An electric heater rated 240 V, 3000 W is to be connected to a 240 V mains supply, through a 10 A fuse.Determine whether the fuse is suitable or not(Solved)
An electric heater rated 240 V, 3000 W is to be connected to a 240 V mains supply, through a 10 A fuse. Determine whether the fuse is suitable or not
Date posted: February 15, 2017. Answers (1)
- When a current of 2.0 A flows in resistor for 10 minutes, 15, 000 joules of electrical energy is dissipated. Determine the voltage across the resistor(Solved)
When a current of 2.0 A flows in resistor for 10 minutes, 15, 000 joules of electrical energy is dissipated. Determine the voltage across the resistor.
Date posted: February 15, 2017. Answers (1)
- State three factors that affect the capacitance of a parallel plate capacitor(Solved)
State three factors that affect the capacitance of a parallel plate capacitor
Date posted: February 15, 2017. Answers (1)
- State the effect of decreasing the distance between the plates of a parallel plate capacitor on the capacitance(Solved)
State the effect of decreasing the distance between the plates of a parallel plate capacitor on the capacitance.
Date posted: February 15, 2017. Answers (1)
- A positively charged electroscope gets discharged when the cap is touched with a finger.(Solved)
Explain how a positively charged electroscope gets discharged when the cap is touched with a finger.
Date posted: February 15, 2017. Answers (1)
- Light from a lamp falls on the cap of a negatively charged electroscope. It is observed that the divergence of the leaf decreases(Solved)
Light from a lamp falls on the cap of a negatively charged electroscope. It is observed that the divergence of the leaf decreases. Explain the observation
Date posted: February 15, 2017. Answers (1)
- In some petrol engines where sparks plugs are used, a capacitor is connected to the distributor suggest the function of the capacitor(Solved)
In some petrol engines where sparks plugs are used, a capacitor is connected to the distributor suggest the function of the capacitor.
Date posted: February 14, 2017. Answers (1)
- Name two factors other than tension, which determine the frequency of sound from a stretched wire at room temperature(Solved)
Name two factors other than tension, which determine the frequency of sound from a stretched wire at room temperature.
Date posted: February 14, 2017. Answers (1)
- What are the necessary conditions for interference to occur in waves(Solved)
State the necessary conditions for interference to occur in waves.
Date posted: February 14, 2017. Answers (1)
- A wire is stretched between two fixed points such that when it is plucked, it produces sound. Explain why the pitch of the sound produced may become lower when the temperature of the surrounding rises(Solved)
A wire is stretched between two fixed points such that when it is plucked, it produces sound. Explain why the pitch of the sound produced may become lower when the temperature of the surrounding rises.
Date posted: February 14, 2017. Answers (1)
- What determines the quality of a musical note?(Solved)
What determines the quality of a musical note?
Date posted: February 14, 2017. Answers (1)
- How does a piece of a Polaroid reduce the sun’s glare?(Solved)
Explain how a piece of a Polaroid reduces the sun's glare.
Date posted: February 14, 2017. Answers (1)
- What characteristic of sound is applied in tuning pianos?(Solved)
What characteristic of sound is applied in tuning pianos?
Date posted: February 14, 2017. Answers (1)
- The pitch of the note produced by a wire depends on the tension in the wire. State the other factor that effects the pitch(Solved)
The pitch of the note produced by a wire depends on the tension in the wire. State the other factor that effects the pitch.
Date posted: February 14, 2017. Answers (1)
- Distinguish between stationary and progressive waves(Solved)
Distinguish between stationary and progressive waves.
Date posted: February 14, 2017. Answers (1)
- State a characteristic of sound, which is determined by overtone(Solved)
State a characteristic of sound, which is determined by overtone.
Date posted: February 14, 2017. Answers (1)
- Name the property of light that shows that it is a transverse wave(Solved)
Name the property of light that shows that it is a transverse wave.
Date posted: February 14, 2017. Answers (1)
- Name the property of light that shows that it is a transverse wave(Solved)
Name the property of light that shows that it is a transverse wave.
Date posted: February 14, 2017. Answers (1)