Electricity Power

What is the commercial unit of electrical energy?

• Joules

• Kilojoules

• Kilowatt-hour

• watt-hour

An electric bulb is connected to a 220V generator. The current is 0.50 A. What is the power of the bulb?

• 440 V

• 220 V

• 110 V

• 55 V

100 J of heat is produced each second in a 4Ω resistor. The potential difference across the resistor will be:

• 30 V

• 10 V

• 20 V

• 25 V

Tags

NGSS.HS-PS2-4

An electric iron draws a current 4 A when connected to a 220 V mains. Its resistance must be

• 1000 Ω

• 55 Ω

• 44 Ω

• none of these

What is the term used to describe the opposition that a device or material offers to the flow of direct current?

• Resistance

• Capacitance

• Inductance

• Conductance

Which of the following is a correct representation of Ohm's Law?

• All of the above

A current of 0.25 A is drawn by a filament of an electric bulb for 5 minutes. Find the amount of electric charge that flows through the

circuit.

• 75 C

• 125 C

• 200 C

• 300 C

36 J of work is done in moving certain charge across two points having a potential difference 1.2 V. Find the magnitude of charge.

• 3 C

• 1/3 C

• 30 C

• 1/30 C

An electric refrigerator rated 250 W operates 10 hour/day. What is the cost of the energy to operate it for 20 days at ₹ 5.00 per kW h?

• ₹ 300

• ₹ 250

• ₹ 200

• ₹ 100

Tags

NGSS.HS-PS3-1

An old air conditioner rated 2500 W connected to 220 V supply is used regularly for 5 hr a day for 30 days. When it is replaced by an inverter air conditioner rated 1500 W used for same time period as stated earlier. What is cost saving percentage if 1 kWhr costs ₹5.

• 6%

• 40%

• 60%

• 94%

Tags

NGSS.HS-ESS3-2

NGSS.HS-ETS1-3