Physics Electricity

Before being distributed through the National Grid, the output of a power station passes through a…

• step-out transformer

• step-in transformer

• step-down transformer

• step-up transformer

Tags

NGSS.HS-PS2-5

A 10 cm length of wire has a reistance of 25 Ω (ohms).

A 30 cm length of the same wire will have a resistance of…

• 50 ohms

• 100 ohms

• 8 ohms

• 75 ohms

In the UK, the live wire is at an alternating potential difference of…

• 0 V

• 120 V

• 230 V

• 390 V

What type of current do cells and batteries provide?

• a.c. only

• d.c. only

• a.c. and d.c.

• neither a.c. nor d.c.

Which of these statements about a diode is true?

• A diode lets current through in only one direction

• A diode lets current through in both directions

• A diode has low resistance in all arrangements

• A diode has zero resistance

Transformers in the National Grid are essential to distribute electricity…

• efficiently

• safely

• fairly

• quickly

Tags

NGSS.HS-ETS1-3

NGSS.HS-PS3-3

An LED is an electrical device. What does 'LED' stand for?

• Low-energy device

• Light-efficient dimmer

• Low-efficiency diode

• Light-emitting diode

A student connects a length of unknown material in series with a battery and an ammeter (which measures current flow). When the circuit is complete, the ammeter reads that no current is flowing. The unknown material is most likely ​ ​ (a)  

• an insulator

• a conductor

• a superconductor

• a semiconductor

According to the above diagram, what is the equivalent resistance of the circuit?

• 0.96 Ω

• 1.21 Ω

• 20 Ω

• 284 Ω

What is the power output in Watts of a lightbulb connected in series to a 1.5 V battery if the current flowing through the circuit is 0.5 A? Record your answer. Be sure to use the correct place value.

Mathematical Equivalence

ON

Tags

NGSS.HS-PS3-5