A ________ filter passes all frequencies within a band between a lower and an upper critical frequency and rejects all others outside this band.

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Question: A ________ filter passes all frequencies within a band between a lower and an upper critical frequency and rejects all others outside this band.
[A].

low-pass

[B].

high-pass

[C].

band-pass

[D].

band-stop

Answer: Option C

Explanation:

No answer description available for this question.

An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with β = 0.1 is used, the lower cut off frequency will be

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Question: An RC coupled amplifier has an open loop gain of 200 and a lower cutoff frequency of 50 Hz. If negative feedback with β = 0.1 is used, the lower cut off frequency will be
[A].

about 50 Hz

[B].

about 5 Hz

[C].

about 2.38 Hz

[D].

about 70.5 Hz

Answer: Option C

Explanation:

New lower cutoff frequency = .

A resistance R, inductance L and capacitance C are in series. The source frequency is adjusted to be equal to resonant frequency. The lower half power frequency is ω1. Another resistance R is added in series with the circuit. The new lower half power frequency will be

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Question: A resistance R, inductance L and capacitance C are in series. The source frequency is adjusted to be equal to resonant frequency. The lower half power frequency is ω1. Another resistance R is added in series with the circuit. The new lower half power frequency will be
[A].

ω1

[B].

less than ω1

[C].

more than ω1

[D].

either more than ω1 or less then ω1

Answer: Option C

Explanation:

As R increases, Q decreases, bandwidth = . Therefore, bandwidth increases. Hence lower half power frequency will be less than ωr.

Close-up images of Mars by the Mariner 9 probe indicated networks of valleys that looked like the stream beds on Earth. These images also implied that Mars once had an atmosphere that was thick enough to trap the sun’s heat. If this were true, something happened to Mars billions of years ago that stripped away the planet’s atmosphere. This paragraph best supports the statement that

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Question: Close-up images of Mars by the Mariner 9 probe indicated networks of valleys that looked like the stream beds on Earth. These images also implied that Mars once had an atmosphere that was thick enough to trap the sun’s heat. If this were true, something happened to Mars billions of years ago that stripped away the planet’s atmosphere.
This paragraph best supports the statement that
[A].

Mars now has little or no atmosphere.

[B].

Mars once had a thicker atmosphere than Earth does.

[C].

the Mariner 9 probe took the first pictures of Mars.

[D].

Mars is closer to the sun than Earth is.

Answer: Option A

Explanation:

The paragraph states that Mars once had a thick atmosphere, but that it was stripped away. The other choices, true or not, cannot be found in the passage.