1st Year

Question 1

1. Calculate the current flowing in a 5∙6kΩ resistance if the voltage across it is 30mV

Answer 1

Question 2

2. Calculate the voltage across a 10kΩ resistance if the current flowing through it is 5mA.

Answer 2

Question 3

3. Calculate the resistance of an electrical circuit if an applied voltage of 100mV causes a current of 200µA to flow.

Answer 3

Question 4

4. Calculate the input resistance of a medical instrument that draws a current of 50µA from a 100mV dc supply.

Answer 4

Question 5

5. Calculate the power dissipated in a 1∙5kΩ resistor subjected to a voltage of 10mV.

Answer 5

Question 6

6. Calculate the power dissipated in a 1∙5kΩ resistor which carries a current of 300mA.

Answer 6

Question 7

7. If a 1kΩ resistor dissipates a power of 500mW calculate the current it carries

Answer 7

Question 8

8. Calculate the power dissipated by a medical instrument that has an input resistance of 1kΩ and draws 400mA from a dc supply.

Answer 8

Question 9

9. A transmitter has an internal resistance of 5Ω and a maximum output voltage on no-load of 2V. Calculate the maximum power it can transmit.

Question 10

10. A medical instrument with an input resistance of 1kΩ is connected to a 600mV dc supply. Calculate the current that it draws from the supply.

Answer 10

Question 11

11. Calculate the power dissipated by a medical instrument with an input resistance of 1kΩ when it is connected to a 900mV dc supply.

Answer 11

Question 12

12. A transmitter has an internal resistance of 6Ω and a maximum output voltage on no-load of 3V. Calculate the maximum power it can transmit

Answer 12

Question 13

What particles are found in the nucleus of an atom?

Answer 13

Protons (positive) and neutrons (neutral).

Question 14

Where are electrons located in an atom?

Answer 14

Electrons orbit the nucleus in discrete energy levels.

Question 15

What is true about the number of protons and electrons in a neutral atom?

Answer 15

They are equal.

Question 16

How does electron binding strength relate to distance from the nucleus?

Answer 16

Outer electrons are less tightly bound as energy levels increase with distance.

Question 17

What is the formula for the maximum number of electrons per orbit?

Answer 17

2n², where n is the orbit number.

Question 18

How is electric current (I) defined?

Answer 18

As the rate of flow of electric charge: I = Q / t

Question 19

What causes current to flow in a conductor?

Answer 19

A potential difference (emf) across the conductor.

Question 20

What is Ohm’s Law?

Answer 20

V = I × R (Voltage = Current × Resistance)

Question 21

How can Ohm’s Law be used in calculations?

Answer 21

To solve for current, voltage, or resistance.

Question 22

What is the basic formula for power in an electrical circuit?

Answer 22

P = V × I

Question 23

What are alternate formulas for power involving resistance?

Answer 23

P = V² / R and P = I² × R

Question 24

What does the Maximum Power Transfer Theorem state?

Answer 24

Maximum power is delivered when load resistance equals source resistance.