Electric Current

Q. Positive charge Q is given to each plate of a parallel plate air capacitor having area of each plate A and separation between them d. Then find: 1. Capacitance of the system 2. Charges appearing on each surface of plates 3. Electric field between the plates 4. Potential difference between the plates 5. Energy stored between the plates

Q. the distance between the two charges 25 microcoulomb anf 36microcoulomb is 11cm

Q. four charges are placed at corners of square having side 10 cm if q is 1 "mu"c then what will be the electric field at centre of square step by step

Q.

Electric current is a scalar quantity but it possesses magnitude and direction. Why?

Q. Electric field due to infinite non conducting sheet of surface charge density sigma at a distance r from it is

Q. 2 point charges 10microC and -10microC are placed 5mm apart. Determine the electric field at a) A point P on the axis of the dipole 15cm away from its center O on the side of the positive charge

Q. Positive and negative charge in 18 cc of water is Options: Should have chosen q = ± 9.63 × 105 C q = ± 1.63 × 105 C q = ± 9.63 × 10–5 C q = ± 2.63 × 10–5 C

Q. Five identical charges q are placed at five corners of a regular hexagon of side l. Find the magnitude of electric field at centre

Q.

Define a unit charge.

Q.

What device converts AC to DC?

Q.

Define the unit of current.

Q.

Why current flows from higher potential to lower potential?

Q.

An electric bulb draw a electric current 0.2A when voltage was 220 volt. Find the amount of electric charge flow in 1 hour

Q.

A $6\Omega$ resistance wire is doubled on itself. Calculate the new resistance of the wire.

Q. Two charges 10 microcoulomb and -10 microcoulomb are placed at points A and B separated by a distance of 10 cm. Find the electric field at a point P on the perpendicular bisector of AB at a distance of 12 cm from its middle point.

Q.

State the laws of resistance.

Q. Question 18 (d)
Explain:
(d) How does the resistance of a wire vary with its area of cross-section?

Q.

Why LED is operated in forward bias?

Q. The electric field due to a point charge at a distance 1 m from it is 900 N/C. The magnitude of the charge is

Q.

The electrical resistivities of copper and aluminium are $1.62\times {10}^{-8}\Omega m$ and $2.63\times {10}^{-8}\Omega m$ respectively. Which is a better conductor? Why?

Q.

If a wire of resistivity $\left(\rho \right)$ is stretched to thrice its initial length, what will be its new resistivity?

Q. if there are 2 charges q and -q then where does the null point of electric field lines lie? Explain pictorially?

Q. A charged wire is bent in the form of a semi circular arc if radius a. If charge per unit length is lambda C/m, the electric field at the centre O is?

Q.

What is the flow of charge called?

Q.

The SI unit of current is ____.

Q. How does increase in temperature of electrolyte decreases the internal resistance of a cell?

Q.

A charge of $2\times {10}^{-2}$ C moves at 30 revolutions per second in a circle of diameter 80 cm. The current linked with the circuit is:

1. 0.6 A

2. 0.2 A

3. 1.2 A

4. 1.6 A

Q.

What is the effect of the length on the resistance of a conductor? How does the resistance of a wire change when its length is

b.halved?

Q. Why electricity as imagination is as blue in colour

Q. What is resistivity?