Question

In: Physics

1. When an RL circuit is connected to a battery, what happens to the potential difference...

1. When an RL circuit is connected to a battery, what happens to the potential difference across the inductor?

It is constant.

It is initially at its maximum value and then decreases exponentially with time.

It is initially at its maximum value and then decreases linearly with time.

It is initially 0 and then increases.

2. If we decrease the resistance in an RL circuit, what happens to the time required for the current to reach, say, 50% of its final value after the battery is connected?

The time is increased.

The time is decreased.

The time is the same.

3. In the two-coil setup in this section, if the current in coil 1 is increasing at a constant rate, which is true?

The induced emf in coil 2 is increasing.

The induced emf in coil 2 is decreasing.

The induced emf in coil 2 is constant.

4. In the two-coil setup in this section, if the current in coil 1 is decreasing at a constant rate, which is true?

The induced emf in coil 2 is constant.

The induced emf in coil 2 is increasing.

The induced emf in coil 2 is decreasing.

Expert Solution

1. Voltage across inductor is at its maximum value and then decreases exponentially with time. As we know that the expression of voltage across inductor can be given as :-

; where v(t) is the voltage across inductor and V is source voltage and T is time constant. As the expression is exponential and decreases with time, so the second option is correct.

2. The equation for the time to 50 % of the final value is given as :-

; where t is the time for current to reach 50% of final value.

Clearly, when the value of R is decreased time for the current to reach 50% of final value will increase.

3. The induced emf for the second coil can be given in terms of mutual inductance as follows :-

e = -M21 (dI1/dt); where M21 is the mutual inductance

Here, rate of change of current in coil 1 is constant, so induced emf will also be constant. Hence, option 3 is true.

4. As per question number 3, same will be case as current is decreasing only, but rate is constant. So the enduced emf will be constant, but with reversed polarity compared to 3 case. Hence, option 1 is correct.

genius_generous answered 3 years ago

1. When a switch is closed in a RL circuit with a battery, which of the...

1. When a switch is closed in a RL circuit with a battery, which of the following statement is TRUE? Back emf is maximum in the beginning and decreases exponentially with time Back emf is zero in the beginning and increases exponentially with time Current is maximum in the beginning and decreases exponentially with time Current is zero in the beginning and increases exponentially with time 2. When an inductor is connected to an AC voltage source with Vmax= 5...

If a circuit consists of a battery connected to multiple resistors, and these resistors are connected...

If a circuit consists of a battery connected to multiple resistors, and these resistors are connected in series, what MUST be the same across each resistor? A. Voltage B. Current C. Resistance D. Power E. None of the above QUESTION 2 If a circuit consists of a battery connected to multiple resistors, and these resistors are connected in parallel, what MUST be the same across each resistor? A. Voltage B. Current C. Resistance D. Power E. None of the...

A circuit has a 2.9 V battery connected in series with a switch. When the switch...

A circuit has a 2.9 V battery connected in series with a switch. When the switch is closed, the battery powers two paths in parallel, one of which has a resistor of resistance R1 = 80 Ω in series with an inductor of inductance L = 1×10−2 H , while the other has a resistor of resistance R2 = 230 Ω . What is the current supplied by the battery at a time t = 0.25 ms after the switch...

A battery is connected across a series combination of two identical resistors. If the potential difference...

A battery is connected across a series combination of two identical resistors. If the potential difference across the terminals is V and the current in the battery is i, then: Which of these statement are true? The potential difference across each resistor is V and the current in each resistor is i The potential difference across each resistor is V/2 and the current in each resistor is i The potential difference across each resistor is V and the current in...

Consider a simple RL circuit consisting of an ideal battery with voltage 30 V , a...

Consider a simple RL circuit consisting of an ideal battery with voltage 30 V , a resistor of resistance 15 Ω, an inductor of inductance 7.0 H, and a switch all in series. The switch is initially open. a) Determine the ratio of the voltage across the resistor to the voltage across the inductor when the current has a value of 1.5 A. b) How much time has elapsed if the voltage across the resistor is 20 V ?

3)When a power source like a battery is connected to a circuit, an electric field pushes...

3)When a power source like a battery is connected to a circuit, an electric field pushes electrons within the conducting wires causing them to flow. The electric field exists due to an uneven build up of charge on the surfaces of the wires (called a surface charge gradient). In this set of problems we will explore a simple model of how this all comes about and emphasize the connection between source charges, electric fields, and voltage differences in the context...

What is the terminal voltage of the battery when the circuit is closed?

A battery of EMF 10 V and internal resistance 3 Ω is connected to a resistor. If the current in the circuit is 0.5 A, what is the resistance of the resistor? What is the terminal voltage of the battery when the circuit is closed?

2. A circuit contains 3 resistors connected in series and no battery. It is a closed...

2. A circuit contains 3 resistors connected in series and no battery. It is a closed circuit and has dimensions of 18 cm by 42 cm. The resistor values are 12, 15 and 18 ohms. A magnetic field directed out of the plane of the circuit changes from 52 T to 0 T in 2.9 sec. a. Sketch the circuit and indicate the direction of the initial magnetic field. b. What is the magnetic flux through the circuit when the...

Three identical light bulbs are connected to a 30V battery in a circuit. Bulb A is...

Three identical light bulbs are connected to a 30V battery in a circuit. Bulb A is on main loop and closest to battery. Bulbs B and C are in parallel and the junction is after Bulb A S1 is in the loop with bulb B and S2 is in loop with bulb C Initially switch 1 is closed and switch 2 is opened. When switch 2 is closed what happens to the brightness of bulbs A,B and C Please explain

Initially, a simple circuit has a battery connected in series by conducting copper wire to a...

Initially, a simple circuit has a battery connected in series by conducting copper wire to a lightbulb. In this configuration, the lightbulb shines brightly. Vivian thinks the lightbulb is too bright and wants to reduce its power output. What change should she make to the circuit? Please explain answer reasoning A. Add another identical lightbulb connected in parallel. B. Replace the conducting copper wire with a smaller diameter copper wire. C. Replace the conducting copper wire with a larger diameter...