PHYSICS ASSIGNMENT ON ELECTRICITY IB

An electrical conductor has a resistance of 5.6kΩ. A potential difference of 9.0V is applied across its ends.

How many electrons pass a point in the conductor in one minute?

• 6.0 × 10²⁰

• 1.0 × 10¹⁹

• 6.0 × 10¹⁷

• 1.0 × 10¹⁶

Which measurements are required to calculate the resistivity of the metal of a wire?

• p.d., current, area, length

• p.d., current, diameter, length

• resistance, area, length

• resistance, length, radius

The graph shows the current/voltage characteristics of a filament lamp.

The resistance of the filament at 4.0 V is

• 250 Ω

• 4 000 Ω

• 8 000 Ω

• 64 000 Ω

A fully charged 12V car battery can supply a charge of 100kC. The car's starter motor requires a current of 200A for an average period of 2.0 s.

Due to a fault, the battery does not recharge. What is the maximum number of times the car's starter motor can be used?

• 21

• 25

• 42

• 250

Four wires are made of the same metal. The cross-sectional areas, lengths, and thermodynamic temperatures of the wires are shown. Which wire has the largest resistance?

• Wire A

• Wire B

• Wire C

• Wire D

Which of the following is a correct statement of Ohm’s law?

• The resistance of a conductor is always constant

• The current in a conductor is always proportional to the potential difference across the conductor.

• The resistance of a conductor increases with increasing temperature.

• The resistance of a conductor is constant only if the temperature of the conductor is constant.

The work done on a positive point charge of magnitude 3.0 nC as it is moved at constant speed from one point to another is 12 nJ. What is the potential difference between the two points?

• 0.0 V

• 0.25 V

• 4.0 V

• 36 V

The graph below shows the variation in current I of the potential difference V across a filament lamp.

The resistance of the lamp when I = 1.5 mA is:

• 950 Ω

• 400 Ω

• 0.95 Ω

• 0.40 Ω

The electric field strength at a point may be defined as:

• The force exerted on a unit positive charge placed at that point.

• The force per unit positive charge on a small test charge placed at that point.

• The work done on a unit positive charge to move the charge to that point from infinity.

• The work done per unit positive charge to move a small test charge to that point from infinity.

The graph shows the variation in the current I with the applied potential difference V in an electrical component.

Which one of the following gives the resistance of the component at point P?

• The gradient of the line at P

• The reciprocal of the gradient of the line at P