Download App

Introduction to Physics — Physics STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 SciencePhysicsIntroduction to Physics2 Marks
Question
Suppose you are told that the linear size of everything in the universe has been doubled overnight. Can you test this statement by measuring sizes with a metre stick? Can you test it by using the fact that the speed of light is a universal constant and has not changed? What will happen if all the clocks in the universe also start running at half the speed?
✓

Answer

No, Yes, No After clock becomes slow, when 1 hr passes in clock, 2 hr passes in reality. l = ct : old clock time 2l = c (2t) : new clock time$\therefore$ l = ct.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "2 Marks Questions" from Introduction to Physics→Introduction to Physics — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Why does an iceberg float on water?
→
It is a common observation that rain clouds can be at about a kilometre altitude above the ground.A typical rain drop is about 4mm diameter. Momentum is mass x speed in magnitude. Estimate its momentum when it hits ground.
→
A gas having volume of 1 liter at 80 cm mercury pressure expands to 1.190 liter in the adiabatic process. If the pressure of the gas is $6 2 . 6 ~ c m$ and it falls to then find the value of $\gamma$.
→
How many metres can a man weighing 60kg climb on the energy from a slice of bread which produces 1,00,000 cal of heat? Assume that the human body works at an efficiency of 28%. Take the average value of g as $9.8ms^{-2}$.
→
Explain why The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection.
→
Figure, shows two coherent sources $\mathrm{S}_1$ and $\mathrm{S}_2$ which emit sound of wavelength $\boldsymbol{\lambda}$ in phase. The separation between the sources is $3 \lambda$. A circular wire of large radius is placed in such a way that $S_1 S_2$ lies in its plane and the middle point of $\mathrm{S}_1 \mathrm{~S}_2$ is at the centre of the wire. Find the angular positions $\theta$ on the wire for which constructive interference takes place.
→
If each square metre of sun's surface, radiates energy at the rate of $6.3 \times 10^7 \mathrm{~J} / \mathrm{m}^2 / \mathrm{s}$ and the Stefan's constant is $5.669 \times 10^{-8} \mathrm{~W} / \mathrm{m}^2 / \mathrm{k}^4$. Calculate the temperature of the sun's energy assuming Stefan's Law applies to the sun's rediation.
→
Write the significant figures of the following :
(i) 0.046
(ii) 4.000
(iii) $0 . 0 6 0$
(iv) $4.08 \times 10^6$
(v) 600700
(vi) 24600
(vii) 600 m
(viii) 7432
(ix) $6 2 1 2 . 0$
(x) 427.071
(xi) 0.0050
(xii) 0.00007032
(xiii) 0.4680
(xiv) 0.007
(xv) 0.046
(xvi) 946.860
(xvii) $0.04340 N / m$
(xviii) 46.000 m
→
Radioactive $^{131}I$ has a half$-$life of $8.0$ days. A sample containing $^{131}I$ has activity $20\mu\text{Ci}$ at $t = 0$.
  1. What is its activity at $t = 4$ days?
  2. What is its decay constant at $t = 4.0$ days?
→
Suppose, in certain conditions only those transitions are allowed to hydrogen atoms in which the principal quantum number n changes by $2. (a)$ Find the smallest wavelength emitted by hydrogen. $(b)$ List the wavelength emitted by hydrogen in the visible range $(380\ nm$ to $780\ nm).$
→