Question 2 :
An electron enters a region where magnetic field (B) and electric field (E) are mutually perpendicular, then

Question 3 :
A current I is passed through a solenoid of n turns per unit length. What is the magnetic filed inside the solenoid ?&#160;<br/>

Question 4 :
Complete the following statements with an appropriate word / term to be filled in the blank space(s).<br/><br/>Magnetic field lines emerge from the _________ pole of a solenoid or a permanent magnet.<br/>

Question 5 :
In a moving coil galvanometer a radial magnetic&#160;field is applied with concave magnetic poles, to&#160;have<br/>A) uniform magnetic field<br/>B) the plane of the coil parallel to field <br/>Choose the correct option among the following&#160;

Question 6 :
<strong>A galvanometer in series with a high resistance is called </strong><br>

Question 7 :
The sensitivity of a moving coil galvanometer increases with the decrease in&#160;<br/>

Question 10 :
In order to increase the sensitivity of a moving coil galvanometer:

Question 11 :
Two long straight wires carry currents 5 A and&#160;10 A in the same direction are separated by 20&#160;cm. The force between wires is<br/>

Question 12 :
The cyclotron frequency of an electrons gyrating in a magnetic field of $$1$$T is approximately<br>

Question 13 :
When two infinitely long parallel wires separated&#160;by a distance of $$1m$$, each carry a current of $$3A$$, the force in newton/metre length&#160;experienced by each will be, (given $$\mu _{0}=4\pi \times 10^{-7}$$ S.I. Units).&#160;<br/>

Question 14 :
$$H^{+} , He^{+}$$ and $$O^{++}$$ ions having same kinetic energy pass through a region of space filled with uniform magnetic field $$B$$ directed perpendicular to the velocity of ions. The masses of the ions $$H^{+}, He^{+}$$ and $$O^{++}$$ are respectively in the ratio $$1 : 4 : 16 $$. As aresult

Question 15 :
A proton of mass $$m$$ and charge $$q$$ is moving in a plane with kinetic energy $$E$$. If there exists a uniform magnetic field $$B$$, perpendicular to the plane of the motion&#160;the portion will move in a circular path of radius

Question 16 :
A current of $$0.6 A$$ produces a deflection of 30 in the tangent galvanometer. Calculate the value of current will produce a deflection of $$60$$.

Question 17 :
A proton ( mass $$m$$, charge $$e$$) projected with a&#160;velocity $$v$$ passes undeviated through a region of&#160;crossed electric and magnetic fields. The velocity&#160;with which an alpha particle (mass $$4m$$, charge $$2e$$) should be projected so that it passes&#160;undeviated through the same region is:&#160;<br/>

Question 18 :
The field due to a wire of $$n$$ turns and radius $$r$$ which carries a current $$I$$ is measured on the axis of the coil at a small distance $$h$$ from the center of the coil. This is smaller than the field at the center by the fraction:<br>

Question 19 :
A moving coil galvanometer of resistance $$100 \space \Omega$$ is used as an ammeter using a resistance $$0.1 \space \Omega$$. The maximum deflection current in the galvanometer is $$100 \space \mu A$$.Find the minimum current in the circuit so that the ammeter shows maximum deflection.

Question 20 :
A charged particle of mass $$m$$ and charge $$q$$ travels on a circular path of radius $$r$$ that is perpendicular to a magnetic field $$B$$. The time taken by the particle to complete one revolution is :

Question 21 :
A long solenoid has $$200$$ turns per $$cm$$ and carries a current of $$2.5\ Amp$$. The magnetic field at its centre is ($$\mu _{0}=4\pi \times 10^{-7} $$Wb/ A-m)

Question 22 :
A solenoid of $$0.4 m$$ length with $$500$$ turns carries a current of $$3 A$$. A coil of $$10$$ turns and of radius $$0.01 m$$ carries a current of $$0.4 A$$. The torque required to hold the coil with its axis at right angles to that of solenoid in the middle point of it is:

Question 23 :
A charged particle $$P$$ leaves the origin with speed $$v=v_0$$ at some inclination with the $$x-$$axis. There is a uniform magnetic field B along the $$x-$$axis. $$P$$ strikes a fixed target $$T$$ on the $$x-$$axis for a minimum value of $$B=B_0$$. If the pitch of the helical path is equal to the maximum distance of the particle from the x-axis, then which of the following are <b>not correct</b>?<br>

Question 24 :
An alternating electric field of frequency 'y' is applied across the dees (radius R) of a cyclotron to accelerate protons (mass m). The operating magnetic field 'B' used and K.E. of the proton beam produced by it are respectively (e = charge of proton).

Question 25 :
<br>Two protons move parallel to each other, keeping distance $$\mathrm{r}$$ between them, both moving with same velocity $$\vec{\mathrm{v}}$$. Then the ratio of the electric and magnetic force of interaction between them is:<br>(c - Velocity of light)