Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

1,681.

Two isotopes of uranium are designed as \(^{238}U\) and \(^{235}U\). The numbers 238 and 235 represent their

A.

atomic numbers

B.

nucleon numbers

C.

proton numbers

D.

neutron numbers

Correct answer is B

neutrons + protons = the nucleus or mass numbers.

U-238 has mass number(proton 92 + neutron 146=238)
U-235 has mass number (proton 92 + neutron 143 =235)

1,682.

An ammeter connected to an a.c circuit records 5.5. The peak current in the circuit is

A.

7.8A

B.

7.1A

C.

3.8A

D.

3.5A

Correct answer is A

\(I_o = I_{rms} \times \sqrt{2} = 5.5 \times 1.41 = 7.8A\)

1,683.

An inductor of inductance 1.0H is connected in series with a capacitor of capacitance 2.0\(\mu F\) in an a.c. circuit. to resonate

A.

112.5Hz

B.

225.0Hz

C.

323.5Hz

D.

707.1Hz

Correct answer is A

fo = \(\frac{1}{2 \pi \sqrt{LC}} = \frac{1}{2 \times 3.14 \sqrt{1 \times 2 \times 10^{-6}}}\)

= 112.5Hz

1,684.

If the direction of the curent in a straight wire is reversed, the magnetic field

A.

remains the same

B.

becomes parallel to the wire

C.

ceases to exist

D.

is oppositely directed

Correct answer is D

No explanation has been provided for this answer.

1,685.