मराठी

If Fuse of 250 Ma, 500 Ma, 1 A, 5 a and 10 a Were Available, Which One Would Be the Most Suitable for Protecting an Amplifier Rated at 240 V, 180 W?

Advertisements
Advertisements

प्रश्न

If fuse of 250 mA, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?  

Advertisements

उत्तर

We will first calculate the current.
Here,
P = 180 W
V = 240 V
Now, power, P = `VxxI`
or, I = P/V = 180/240 = 0.75 A
So, a fuse of 1 A will be most suitable. 

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 5: Magnetic Effects of Electric Current - Exercise 5 [पृष्ठ ११४]

APPEARS IN

लखमीर सिंह Physics [English] Class 10
पाठ 5 Magnetic Effects of Electric Current
Exercise 5 | Q 8 | पृष्ठ ११४

व्हिडिओ ट्यूटोरियलVIEW ALL [2]

संबंधित प्रश्‍न

An electromagnet does not attract a piece of iron.


An electric bell has an electromagnet. 


Fill in the following blank with suitable words: 

The magnetic effect of a coil can be increased by increasing the number of ........... increasing the ........... or inserting an ........... core.


Fill in the following blank with suitable words:

 If a coil is viewed from one end and the current flows in an anticlockwise direction, then this end is a ........... pole.


When the switch S is closed in the figure given below, the pointer of the galvanometer moves to the right.  

 

If S is kept closed, will the pointer:

(a) return to zero?
(b) stay over on the right?
(c) move to the left and stay there
(d) move to and fro until S is opened


How should the electric lamps in a building be connected so that the switching on or off in a room has no effect on other lamps in the same building?


In the Activity shown below, how do we think the displacement of rod AB will be affected if

  1. current in rod AB is increased
  2. a stronger horse-shoe magnet is used
  3. length of the rod AB is increased?
  • Take a small aluminium rod AB (of about 5 cm). Using two connecting wires suspend it horizontally from a stand, as shown in Fig.
  • Place a strong horse-shoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. For this put the north pole of the magnet vertically below and south pole vertically above the aluminium rod (Fig.).
  • Connect the aluminium rod in series with a battery, a key and a rheostat.
  • Now pass a current through the aluminium rod from end B to end A.
  • What do you observe? It is observed that the rod is displaced towards the left. You will notice that the rod gets displaced.
  • Reverse the direction of current flowing through the rod and observe the direction of its displacement. It is now towards the right.
  • Why does the rod get displaced?


A current-carrying rod, AB, experiences a force perpendicular to its length and the magnetic field. Support for the magnet is not shown here, for simplicity.


Observe the following diagram and choose the correct alternative:


When the resistance of a conductor increases, the current ____________ .

(ii) Global warming is a desirable aspect of the intensified greenhouse effect.


Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:  
(a) the current is passed through the wire.  
(b) the current through the wire is increased
(c) the current through the wire is reversed. 


Draw a neat labelled diagram to show the magnetic effect of electric current.


Identify the given figure, write the labels of it.


Explain the magnetic field created around a straight current carrying conductor with the help of a diagram.


Magnetic effect of current was discovered by ______.


Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.


______ cells cannot be recharged after use.


A wire with green insulation is usually the live wire of an electric supply.


A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminium rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions: 

  1. Why does the rod get displaced on passing current through it?
  2. State the rule that determines the direction of the force on the conductor AB.
    1. If the U-shaped magnet is held vertically and the aluminium rod is suspended horizontally with its end B towards due north, then on passing current through the rod from B to A as shown, in which direction will the rod be displaced?
    2. Name any two devices that use current carrying conductors and magnetic fields.

OR

Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×