Question
Three appliances are connected in parallel to the same source which provides a voltage of 220V. A fuse connected to the source will blow if the current from the source exceeds 10A. If the three appliances are rated at 60W, 500W and 1200W at 220V, will the fuse blow?

Answer

Voltage of power supply, V = 220V
Power rating of the first appliance = 60W
So, current drawn by the first appliance $=\frac{60}{220}=0.27\text{A}$
Power rating of the second appliance = 500W
So, current drawn by the second appliance $=\frac{500}{220}=2.27\text{A}$
Power rating of the first appliance = 1200W
So, current drawn by the first appliance $=\frac{1200}{220}=5.45\text{A}$
Net current drawn by all the appliances = 0.27 + 2.27 + 5.45 = 5.99A
It is given that the rating of the fuse is 10 A. It will not blow when all the appliances are used together because current capacity of the fuse is more than the value of current drawn by the device.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A dentist’s mirror has a radius of curvature of 3cm. How far must it be placed from a small dental cavity to give a virtual image of the cavity that is magnified five times?
What are the limitations of energy that can be harnessed from the sea?
If the image formed by a lens for all positions of the object placed in front of it is always virtual, erect and diminished, state the type of the lens. Draw a ray diagram in support of your answer. If the numerical value of focal length of such a lens is 20 cm, find its power in new cartesian sign conventions.
What is short circuiting? State one factor/ condition that can lead to it. Name a device in the household that acts as a safety measure for it. State the principle of its working.
Draw a diagram to show how a converging lens held close to the eye acts as a magnifying glass. Why is it usual to choose a lens of short focal length for this purpose rather than one of long focal length?
Show how you would connect two 4 ohm resistors to produce a combined resistance of:
  1. 2 ohms.
  2. 8 ohms.
The image formed by a spherical mirror is real, inverted and is of magnification - 2. If the image is at a distance of 30 cm from the mirror, where is the object placed ? Find the focal length of the mirror. List two characteristics of the image formed if the object is moved 10 cm towards the mirror.
A p.d. of 10V is needed to make a current of 0.02A flow through a wire. What p.d. is needed to make a current of 250mA flow through the same wire?
State what would happen to the direction of rotation of a motor if:
  1. The current were reversed.
  2. The magnetic field were reversed.
  3. Both current and magnetic field were reversed simultaneously.
With the help of a labelled diagram, explain why a tank full of water appears less deep than it actually is.