Advertisements
Advertisements
Question
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in Figure. In the field an electron and a proton move as shown. The electron and the proton experience

Options
forces both pointing into the plane of paper
forces both pointing out of the plane of paper
forces pointing into the plane of paper and out of the plane of paper, respectively
force pointing opposite and along the direction of the uniform magnetic field respectively
Advertisements
Solution
forces both pointing into the plane of paper
Explanation -
The direction of the current is taken as opposite to the flow of electron or in the direction of the flow of protons.
In the given figure, the proton and electron are moving in the opposite direction to each other and perpendicular to the direction of the magnetic field. So, current due to both electron and proton are in the same direction. Hence, the forces acting on both will be in the same direction. By Fleming's left-hand rule the direction of force is pointing into the plane of the paper.

APPEARS IN
RELATED QUESTIONS
An electromagnet does not attract a piece of iron.
Which effect of current can be utilised in detecting a current carrying wire concealed in a wall?
Name the scientist who discovered the magnetic effect of current.
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.
If the direction of electric current in a solenoid when viewed from a particular end is anticlockwise, then this end of solenoid will be:
(a) west pole
(b) south pole
(c) north pole
(d) east pole
The direction of current flowing in the coil of an electromagnet at its two ends X and Y are as shown below:
What is the polarity of end X?
What is the polarity of end Y?
Name and state the rule which you have used to determine the polarities.
A coil is connected to a galvanometer. When the N-pole of magnet is pushed into the coil, the galvanometer deflected to the right. What deflection, if any, is observed when:
the N-pole is removed?
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?
(b) State whether the following statements are true or false:
(i) Magnetic poles exist in pairs.
(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.
Read the given passage and answer the following questions:
The home electrical connection consists of ‘live’, ‘neutral’ and ‘earth’ wires. The ‘live’ and the ‘neutral’ wires have potential difference of 220 V. The ‘earth’ is connected to ground. Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives a way the two wires come in contact with each other and a large current flows through it producing heat. If any inflammable material (such as wood, cloth, plastic, etc.) exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measure.
- Name the two wires having potential difference of 220 V.
- What is a short circuit?
- Write the function of a fuse.
Draw a neat labelled diagram to show the magnetic effect of electric current.
Identify the given figure, write the labels of it.

What is that instrument which can detect the presence of electric current in a circuit?
In the arrangement shown in Figure there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then

Unscramble the following words:
HTRCO
Boojho made an electromagnet by winding 50 turns of wire over an iron screw. Paheli also made an electromagnet by winding 100 turns over a similar iron screw. Which electromagnet will attract more pins? Give reason.
Edison used a ______ wire coil is a vacuum glass and discovered the first electric bulb in 1879.
The figure given below shows the magnetic field around the conductor. Study it and answer the questions:

- What changes are caused by increasing current?
- What do you see when the magnetic needle is kept a little away from the wire?
- In the second part of the figure, the iron filings arrange themselves in a circular manner around the wire. Why does this happen?
Make four electromagnets with 20, 40, 60 and 80 turns. Connect them one by one to a battery of 2 cells. Bring the electromagnet near a box of pins. Count the number of pins attracted by it. Compare the strengths of the electromagnets.
