امتحان شهر نوفمبر ||| Physics

The magnetic flux density produced around a carrying current wire increase by

magnetic flux density =0 at a point in a field of two straight parallel wires carrying a current that flows in opposite directions

In the shown figure a resistance wire in the form of an equilateral triangle the current enters from point A and emerges from point C, so the total magnetic flux at point P is:

Two long parallel wires A,B carry equal currents in the same direction, , so the total magnetic flux density at midpoint is ………

if the the magnitude of the magnetic field at distance from a very long straight, current carrying wire is B, at what distance from  the wire will the field have magnitude 3B?…….

in the opposite  figure , if the distance between the two wires 4 d. so , the natural point is the …… point.

if the value of the magnetic flux density at point X is B then the value of the magnetic flux density at point is ………

Two currentsI,2I pass in two parallel wires as in the figure, when moving wire Y away from wire X the magnetic flux density at point C ………

solenoid of magnetic field intensity at its axis is B if it is uniformly stretched to double A of its length the flux, B becomes.

In which of the following coils the magnetic flux density at its center is the maximum value ?

a circular coil formed of one turn carries electric current intensity I, if the magnetic flux density at its center is B1 and then it is reshaped to another circular coil of N turns and carried the same current intensity, then the magnetic flux density at its center will be ………

In the opposite figure a circular wire ring and a straight wire placed at the position x in the same plane of the ring and both carries electric current its intensity I so that resultant magnetic flux density at the center of the ring c is B and when the wire is moved to position y the magnetic flux density at point c becomes ………

If the magnetic flux density at a point inside a solenoid on its axis is B , then the radius of the solenoid is halved , the new magnetic flux density becomes ……….

A circular loop of turns N1 radius r passes through it electric current I if the magnetic flux at  its center is B and its turn are far away from each other to become a  solenoid of length 20 r and passes through it the same current, so the magnetic flux  density at the mid of its axis is ………

The kind of force between two wires carrying current depends on

As the wire (A) carries 4 A and wire (B) carries current2 A; both of similar length so the ratio between the force affecting wire (B) to the force affecting the wire, (A) is … 1

In the given figure AB represen­­ts a thick straight wire 1 meter long, its weight is 0.4 Newton. It is vertically suspended by means of two elastic springs in a uniform magnetic field of flux density 0.5 Tesla directed inwards into the paper. The tension in the two springs vanishes when an electric current passes in the wire of intensity……….

The ratio of the force acting on a wire carrying current and placed perpendicular to a magnetic field to the force acting on same wire which carries the same electric current when making an angle of 30with the same magnetic field is

The torque (t) acting on a coil carrying an electric current and placed in a uniform magnetic field becomes maximum when the plane of the coil is ……… the direction of the field.

1. Two circular coils carrying currents having the same number of turns, the two coils of radii 3 cm and 6 cm and they have equal magnetic dipole moments. The radio between the currents through the coils is……

A galvanometer of resistance “R” the shunt resistance, which decreases its sensitivity to one fifth is

On joining the shunt resistance to the’ coil of galvanometer the resistance of ammeter …

A galvanometer of sensitivity 2/∘mA has a coil of resistance 100 Ω.If the galvanometer coil is connected to a battery of emf 5 V with negligible internal resistance, what will the angle of deflection of the galvanometer pointer be?

When a shunt is connected to the coil of galvanometer:

Two voltmeters A and B have the same measuring range. If the resistance of voltmeter A is greater than the resistance of voltmeter B, how do the sensitivities of the two voltmeters compare to each other?

A voltmeter can measure a maximum potential difference of 4 V and has a resistance of 3‎ ‎000 Ω.When a multiplier resistor 𝑅m is connected to the voltmeter in series, its measuring range increases by 12 V.Calculate the value of 𝑅

A voltmeter that has a resistance 𝑅can measure potential difference up to 𝑉.If we added a multiplier resistance of value 2𝑅 in series to it, what will the maximum potential difference it can measure be?

A galvanometer that has a resistance of 50 Ω and can measure a current up to 3 mA is connected in series with a multiplier resistor 𝑅m to form a voltmeter. The following graph represents the relation between the potential difference across the voltmeter and the current passing through it. Calculate the value of the multiplier resistor.

A galvanometer is connected in series to a variable multiplier resistor to construct a voltmeter. The graph below represents the relation between the maximum potential difference the voltmeter can measure and the value of the multiplier resistor. Calculate the value of the resistance of the galvanometer.

As 400 ohm resistance makes the pointer of galvanometer deflects for half scale so the resistance which provides third scale deflection equals………      ohm.

If an ohmmeter deflects to half its scale when it is connected to a resistor of resistance 𝑅,what is true about the value of 𝑅?

What will the deflection of an ohmmeter be when connected to a resistance equal to half its internal resistance?

The figure below shows the scale of an ohmmeter. From the data in the figure, calculate the internal resistance of the ohmmeter