Electric Energy and Electric power -quiz

If electrical power costs $0.13/kwh, and I use 9 x 10⁸ Joules of electrical energy, what will I be charged?

(1 kWh = 3.6 * 10⁶J)

• $10.5

• $25.2

• $32.5

• $40.2

Tags

NGSS.HS-PS3-1

A resistor operated at 240 V dc is rated at 2.40 kW.

(a) What is the normal operating current through the resistor?

(b) What is the resistance of the resistor?

(1kW=1000W)

• (a) 10 A . (b) 24 Ω

• (a) 24 A . (b) 24 Ω

• (a) 10 A . (b) 20 Ω

• (a) 0.010 A . (b) 14000 Ω

An instrument is rated at 280 W if it is connected across a 110-V dc power supply.

(a) What current does it draw under normal operation?

(b) What is its resistance?

• (a) 0.20 A (b) 360 Ω

• (a) 44 A (b) 2.5 Ω

• (a) 2.5 A (b) 44 Ω

• (a) 0.2 A (b) 44 Ω

A 250-W light bulb is connected across a 110-V dc power supply. What current will flow through this bulb?

• 0.90 A

• 0.26 A

• 0.60 A

• 2.27 A

A 130-W light bulb is operated by a 120-V dc source. What is the resistance of this bulb?

• 210 Ω

• 8.5 × 10^-3 Ω

• 111 Ω

• 230 Ω

A light bulb operating at a dc voltage of 200 V has a resistance of 150 Ω. How much power is dissipated in this bulb?

• 100 W

• 160 W

• 267 W

• 200 W

When 6.00 A is flowing through an 15.0Ω device, how much power is being dissipated in the device?

• 500.0 W

• 540 W

• 250 W

• 2.50 kW

How much energy does a 200 W light bulb use in 8.0 hours?

• 0.80 kWh

• 1.6 kWh

• 1.3 kWh

• 80 kWh

Tags

NGSS.HS-PS3-1

The power of an appliance is...

• the amount of voltage going through it 
• the amount of energy transferred per second
• the amount of charge that passes through per second

Calculate the electric power of an electrical appliance in which 20 A of current is flowing through a resistor of 3 ohms.  

• 180 W

• 1200 W

• 2.50 A

• 225 KJ