If a projectile explods in mid air then just before and just after explosion, choose correct option(s)

Correct Answer - D The speed of all electromagnetic waves is same in vaccum.

D. Both A and R are true but R does not explain A.

Correct Answer - C `vecv=ahati+6hatjrArru cos theta=a` and `usin theta=b` `tantheta=(b)/(a)` also `tan theta=(4)/(n)=(4)/(2)=2` `therefore (b)/(a)=2 rArr b=2a`

Correct Answer - B `vev=6hati+8hatj` `rArr u cos theta=6` and `u sin theta=8` `R=(2(u sin theta)(u cos theta))/(g)=(2xx6xx8)/(10)=(48)/(5)` R=9.6m

Correct Answer - B The equation of combustion is: `C_(x)H_(y)+(x+(x)/(4))O_(2) to xCO_(2)+(y)/(2)H_(2)O` `vmL V(x+(x)/(4))mL " " xV` `"Volume of "CO_(2)=xV=2V` `therefore x=2` Contraction in volume after explosion `="Volume of gaseous reactants"-"Volume...

Correct Answer - C `(c )` The total number of arrangments is `(11!)/(2!2!2!)=(11!)/(8)` The number of arrangements in which `CE,H,I,S` appear in that order `"^(11)C_(5)(6!)/(2!2!2!)=(11!)/(8*5!)` `:.` Required Proability `=((11!)/(8*5!))/((11!)/(8))=(1)/(120)`

Correct Option is (C) \(60^\circ\) Given, H = 0.433R We know that , \(H = \frac{u^2sin^2 \theta}{2g} , R = \frac{u^2sin^2 \theta}{g}\) \( \frac{u^2sin^2 \theta}{g} = 0.433 \frac{u^2sin^2 \theta}{g}\) \(\frac{sin^2 \theta}{2g} = 0.433 . 2 \ sin...

Correct Option is (B) 125m \(H_{max} = \frac{u^2}{2g}\) \(H_{max} = \frac{50 \times 50}{2 \times 10}\) \(H_{max} = 125 m\)