A long solenoid has 800 turns per metre of the length of the solenoid. A current of 1.6 A flows through it. What is the magnetic induction at the end of the solenoid on its axis?

1.	\(16 \times 10^{-4}~\mathrm T\)	2.	\(8 \times 10^{-4}~\mathrm T\)
3.	\(32 \times 10^{-4}~\mathrm T\)	4.	\(4 \times 10^{-4}~\mathrm T\)

A cell is connected between the points A and C of a circular conductor ABCD of centre O with an angle of AOC = 60°.
If B₁ and B₂ are the magnitudes of the magnetic fields at O due to the currents in ABC and ADC respectively, the ratio B₁: B₂ will be:        
     

1. 0.2                             

2. 6                                    

3. 1

4. 5                    

What is the result of an electric charge in uniform motion?

Two particles each of mass m and charge q are attached to the two ends of a light rigid rod of length 2R. The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. What is the ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod?

1. $\frac{q}{2m}$                               

2. $\frac{q}{m}$

3. $\frac{2q}{m}$                              

4. $\frac{q}{\mathrm{\pi m}}$ 

By which relation is the deflection of the coil θ related to the electrical current i in a moving coil galvanometer?

1. $i\propto \tan \theta$                 

2. $i\propto \theta$ 

3. $i\propto {\theta }^2$                    

4. $i\propto \sqrt{\theta }$ 

Three long, straight, and parallel wires carrying currents of 30 A, 10 A, and 20 A in P, Q, and R, respectively, are arranged as shown in the figure. What is the force experienced by a 10 cm length of wire Q?

When a positively charged particle moves in an x-y plane, its path abruptly changes due to the presence of electric and/or magnetic fields beyond P. The curved path is depicted in the x-y plane and is discovered to be noncircular. Which of the following combinations is true?
          
1. \(\overrightarrow{\mathrm{E}}=0 ; \overrightarrow{\mathrm{B}}=\mathrm{b} \hat{\mathrm{i}}+\mathrm{c} \widehat{\mathrm{k}}\) 
2. \(\overrightarrow{\mathrm{E}}=\mathrm{ai} ; \overrightarrow{\mathrm{B}}=\mathrm{c} \widehat{\mathrm{k}}+\mathrm{a} \hat{\mathrm{i}}\)
3. \(\vec{E}=0 ; \vec{B}=c \hat{j}+b \widehat{k}\)
4. \(\overrightarrow{\mathrm{E}}=\mathrm{ai} ; \overrightarrow{\mathrm{B}}=c \widehat{\mathrm{k}}+\mathrm{b} \hat{\mathrm{j}}\)

Two insulated rings, one of a slightly smaller diameter than the other, are suspended along their common diameter as shown. Initially, the planes of the rings are mutually perpendicular. What happens when a steady current is set up in each of them?

A charge Q is uniformly distributed on a ring of radius R made of an insulating material. If the ring rotates about the axis passing through its centre and normal to the plane of the ring with constant angular speed ω, then what will be the magnitude of the magnetic moment of the ring?

1. $Q\omega R^2$
2. $\frac{1}{2}Q\omega R^2$
3. $Q{\omega }^{2}R$
4. $\frac{1}{2}Q{\omega }^{2}R$

Two long parallel copper wires carry currents of 5 A each in opposite directions. If the wires are separated by a distance of 0.5 m, then the force between the two wires will be: