Physics Past Questions and Answers

Question 4871:

A girl of mass $65kg$ falls horn a bridge that $50m$ above the water. Calculate her kinetic energy after falling foings sees.

A. $1125J$
B. $28125J$
C. $9375J$
D. 812501

Question 4872:

Which of the following is a mechanical wave?

A. Micro wave
B. Water wave
C. $)$-ray
D. Infra-red ray

Question 4873:

The half-life of the radioactive substance of mass $100g$ is 30 minutes. What fractiods of the onginal mass is left over after $3hrs$ ?

A. $3.125$
B. $6.25$
C. $1.5625$
D. $0.02563$

Question 4874:

Two resistors $12\mathrm{\Omega }$ and $8\mathrm{\Omega }$ are connected in parallel, if the power developecin $12\mathrm{\%}$, resistor is $6w$, determine the power developed in $3.32$ resistor.

A. $9w$
B. $12w$
C. $16w$
D. $24w$

Question 4875:

How long will a 60 wart element take to heat water of mass $9.5kg$ at ${20}^{\circ }C$ to ${90}^{\circ }C$. Neglect heat loss (S.H. C. of water $=4200jk{g}^{-1}{K}^{-1}$ )

A. 350 secs
B. 1260 secs
C. $2100secs$
D. 1500 secs