Electric Charge and Energy Calculations

The video tutorial covers 9th standard science, focusing on electric charge and current. It includes solving five problems: calculating the number of electrons in a charge, determining current from charge and time, finding electric charge through a lamp, calculating energy from a cell's EMF, and computing potential difference across a heater. Each problem is broken down step-by-step, with calculations explained in detail.

How many electrons are present in a charge of 1 Coulomb?

• 9.1 x 10^19

• 1.6 x 10^19

• 6.25 x 10^18

• 3.2 x 10^18

What is the current when 25 Coulombs of charge pass through a wire in 50 seconds?

• 0.5 A

• 1 A

• 2 A

• 0.25 A

If a lamp is switched on for 1 hour with a current of 0.2 A, what is the total charge passing through it?

• 36 C

• 72 C

• 18 C

• 144 C

What is the energy provided by a cell with an EMF of 1.5 V to drive 0.5 Coulombs of charge?

• 0.75 J

• 1.5 J

• 2.25 J

• 3 J

Given a charge of 2 x 10^4 C flows through an electric heater converting 5 x 10^6 J of energy, what is the potential difference across the heater?

• 500 V

• 750 V

• 250 V

• 1000 V