Question

1. a transistor radio uses 2 amps of current when it is run by a 9 volt battery. what is the resistance in the radio circuit?
2. a current of 5 amps flows through a lamp when it is connected to a 110 volt power source. what is the resistance of the lamp?
3. an e.m.f. of 75 volts is placed across a 15 ohm fixed resistor. what current flows through the resistor?

10.a motor with a resistance of 32ω is connected to a voltage source. four amps of current flows in the circuit. what is the voltage of the source?

1. a resistance of 30ω is placed in a circuit with a 90 volt battery. what current flows in the circuit?

12.what current flows through a 15 ohm fixed resistor when it operates on a 120 volt outlet?
13.the resistance of an electric stove burner element is 11 ohms. what current flows through this element when it runs off a 220 volt line?
14.what voltage is applied to a 20 ohm fixed resistor if the current through the resistor is 1.5 amps?
15.what is the resistance of a lamp that is connected to a 110 voltage source that draws 2 amps of current?

Explanation:

7.

Step1: Recall Ohm's law formula

$R=\frac{V}{I}$, where $R$ is resistance, $V$ is voltage and $I$ is current.

Step2: Substitute given values

Given $V = 9$ volts and $I=2$ amps. So $R=\frac{9}{2}= 4.5$ ohms.

Step1: Use Ohm's law formula

$R=\frac{V}{I}$

Step2: Substitute values

Given $V = 110$ volts and $I = 5$ amps. So $R=\frac{110}{5}=22$ ohms.

Step1: Rearrange Ohm's law for current

$I=\frac{V}{R}$

Step2: Substitute values

Given $V = 75$ volts and $R = 15$ ohms. So $I=\frac{75}{15}=5$ amps.

Answer:

$4.5$ ohms

8.