Physics 2nd Paper CQ-Sylhet Board-2023

Define surface density of charge.

Charge of a body is $-0.8 \mathrm{C}$ - Is it possible? Explain.

Find the distance between the plates of the capacitor $\mathrm{C}_{3}$ in the fig-1. (in vacuum)

In which circuit the capacitor ' $\mathrm{C}_{1}$ ' will store energy more or remain same? Explain with mathematical analysis.

Define shunt.

What do you mean by temperature coefficient of resistance of Nickel is $6 \times 10^{-3}{ }^{\circ} \mathrm{C}^{-1}$ ?

According to circuit-1 find the value of electric current passing through the external resistance $R$.

Potential difference will be changed across the external resistance ' $R$ ' due to the change in combination of cellsExplain with mathematical analysis according to the circuits 1 and 2.

What is energy band in solid material?

Explain "reverse saturated current" in $\mathrm{p}$-n junction diode.

Find collector-emitter voltage $\left(\mathrm{V}_{\mathrm{CE}}\right)$ in the circuit.

According to the stem, the transistor circuit is acting as a voltage amplifier-Explain with mathematical analysis.

Define dielectric constant.

Electric field intensity is maximum at the surface of a charged sphere-Explain.

Find electric potential at the point $D$.

If another unit positive charge is placed at the point $A$ then which direction it will move? Explain with mathematical analysis.

Define time dilation.

In X-ray tube target have high melting point-Why?

Find the threshold wavelength of the potassium metal.

What will be the change in stopping potential of the given metal due to the change in wavelength of incident ray in Raisa's experiment? Explain with mathematical analysis.