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.

761.

Calculate the electric field intensity between two plates of potential difference 6.5V when separated by a distance of 35cm.

A.

18.57NC\(^{-1}\)

B.

53.06N C\(^{-1}\)

C.

2.28NC\(^{-1}\)

D.

0.80NC\(^{-1}\)

Correct answer is A

Electric Field Intensity (E) = \(\frac{v}{d}\)

= \(\frac{\text{potential difference}}{\text{distance}}\)

= \(\frac{6.5v}{35cm}\)

= \(\frac{6.5}{35 \times 10^{- 2}}\)

= 18.57NC\(^{-1}\)

762.

Which of the following is not an electromagnetic radiation?

A.

x - ray

B.

Radio waves

C.

sunlight

D.

sound waves

Correct answer is D

Electromagnetic waves do not require any material medium, but sound waves is a mechanical wave that require a material medium

763.

Which is the incorrect formula for a body accelerating uniformly?

A.

a = v2 − \(\frac{u^2}{2}\)

B.

v2 = u2 + 2as

C.

s = ut + \(\frac{1}{2}\) at2

D.

v2 − u2= 2as

Correct answer is A

Look through the equations of motion

764.

Two angles of a pentagon are in the ratio 2:3. The others are 60o each. Calculate the smaller of the two angles

A.

72o

B.

100o

C.

120o

D.

144o

Correct answer is D

The diagram given simple illustrates that a pentagon contains three \(\Delta\)s.

Two angles which are in the ratio 2:3 will have actual values 2xo, 3xo respectively. Thus 2xo + 3xo + 3 x 60 = 3x sum of angles of \(\Delta\)a

i.e. 5xo + 180o = 3 x 180o

5xo + 180o = 540o

5xo = 540o - 180o

5xo = 360o

xo = \(\frac{360^o}{5}\)

= 72o

Hence, the smaller of the two angles is

2 x 72o = 144o

765.

Let \(\Delta\)x be the uncertainty in the measurements of position and \(\Delta\)p the uncertainty in measurement of momentum. The uncertainty principle relation is given as

A.

\(\Delta\)x . \(\Delta\)p = h

B.

\(\Delta\)x . \(\Delta\)p \(\leq\) = h

C.

\(\Delta\)x . \(\Delta\)p \(\geq\) = h

D.

\(\Delta\)x . \(\Delta\)p > h

Correct answer is C

No explanation has been provided for this answer.