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.

1,411.

When a man moves toward a plane mirror at a speed of 6m/s, the distance the man and his image increased at a speed of?

A.

2 m/s

B.

4 m/s

C.

12 m/s

D.

14 m/s

Correct answer is C

d = y, s = 6 m/s (The Man & Plane Mirror)

d – δy, s = (5 &ndash ;6) m/s (The Man and Image)

d2 ÷ s1 = d2 ÷ s2, y ÷ 6 = 2y ÷ s + 6

Y (s + 6) = 2y × 6

s + 6 = 12

So = 12 – 6 = 6

Since S + 6 = 0

Then, S = 6 (substitute the value of S i.e S = 6)

Into S + 6 = 0

∴So = S + 6 = 6 + 6 = 12 m/s

∴ S = 12 m/s

1,412.

Volatile liquids usually

A.

Have high boiling points

B.

have low boiling points

C.

have high densities

D.

have high melting points

Correct answer is B

Volatile liquids (i.e. Ammonia or Freon) are usually have low boiling point

1,413.

Efficiency of a transformer is equal to

A.

Efficiency of transformer = (secondary coil ÷ primary coil) × 100%

B.

Efficiency of transformer = (mechanical advantage ÷ velocity ratio) × 100%

C.

Efficiency of a transformer = (Number of turns in the secondary coil ÷ Number of turns in the primary coil) × 100%

D.

Efficiency of a transformer = (power developed in the secondary coil ÷ power supplied to the primary coil) × 100%

Correct answer is D

Efficiency of a transformer = (power developed in the secondary coil ÷ power supplied to the primary coil) × 100%

1,414.

Which one of the following is a vector quantity?

A.

Temperature gradient

B.

Mass

C.

Work

D.

Time

Correct answer is A

Temperature gradient(Tg) = DT ÷ L = T2 – T1 ÷ L

i.e– it is the ratio of an increment in temperature to the length

Hence, Temperature gradient (Tg) has defined direction alongside with magnitude

And it is a vector quantity

Mass, work & Time are scalar quantity

1,415.

The eyeball consists of a round tough white skin called

A.

Sclerotic

B.

Choroid coal

C.

Optical fiber

D.

Accommodation

Correct answer is A

Sclerotic coat (sclera) is the tough outer coat of the eye that coves the eyeball (ii) sclerotic coat is modified in front of the eye to from a transparent and horny window