A capacitor of 8 Fis connected as shown in the figure. Charge on the plates of the capacitor

• 32 C

• 40 C

• 0 C

• 80 C

Four metal plates are arranged as shown in the figure. Capacitance between X and Y (A ➔ Area of each plate, d ➔ distance between the plates) is

• $\frac{3}{2} \frac{{\mathrm{\epsilon }}_0\mathrm{A}}{\mathrm{d}}$

• $\frac{2{\mathrm{\epsilon }}_0\mathrm{A}}{\mathrm{d}}$

• $\frac{2}{3} \frac{{\mathrm{\epsilon }}_0\mathrm{A}}{\mathrm{d}}$

• $\frac{3{\mathrm{\epsilon }}_0\mathrm{A}}{\mathrm{d}}$

Mobility of free electrons in a conductor is

• directly proportional to electron density

• directly proportional to relaxation time

• inversely proportional to electron density

• inversely proportional to relaxation time

Variation of resistance of the conductor with temperature is as shown

The temperature coefficient (α) of the conductor is

• $\frac{{\mathrm{R}}_0}{\mathrm{m}}$

• mR₀

• m²R₀

• $\frac{\mathrm{m}}{{\mathrm{R}}_0}$

Potential difference between A and B in the following circuit

• 4 V

• 5.6 V

• 2.8 V

• 6 V

In the following network, potential at O is

• 4 V

• 3 V

• 6 V

• 4.8 V

27.

Effective resistance between A and B in the following circuit                                 

• 10 Ω

• 20 Ω

• 5 Ω

• $\frac{20}{3} \mathrm{\Omega }$

Two heating coils of resistances 10 Ω and 20 Ω are connected in parallel and connected to a battery of emf 12 V and internal resistance 1 Ω. The power consumed by them are in the ratio

• 1 : 4

• 1 : 3

• 2 : 1

• 4 : 1

A proton is projected with a uniform velocity v along the axis of a current-carrying solenoid, then

• the proton will be accelerated along the axis

• the proton path will be circular about the axis

• the proton move along helical path

• the proton will continue to move with velocity v along the axis

In the cyclotron, as radius of the circular path of the charged particle increases (ω = angular velocity, v = linear velocity)

• both ω and v increase

• ω only increases, v remains constant

• v increases, ω remains constant

• v increases, ω decreases