TEST SERIES FOR AIPMT (HALF SYLLABUS) - Career Point

Q.44 At time t = 0, N1 nuclei of decay constant λ1 and
N2 nuclei of decay constant λ2 are mixed. The
decay rate of mixture is -
( 1 2 ) t
(1) N N e
λ + λ −
−
⎛
(2) −
⎜
⎝ N
1 2
N 1 ⎞ −(
λ1+
λ2
) t
⎟
⎟e
2
⎠
−λ
t
−λ
t
1 1 1 2
( 1 2 ) t
1 1N
2 2e
λ + λ −
λ λ
1
2
(3) − ( N λ e + N λ e )
(4) − N
Q.45 Electrons with de-Broglie wavelength λ fall on
the target in an X-ray tube. The cut-off
wavelength of the emitted X-rays is
mc
(1)
h
2
2 λ
2h
λ 0 =
(2) 0
mc
= λ
2
2
3
2m
c λ
(3) λ0 =
(4) λ0 = λ
2
h
Q.46 The intensity of gamma radiation from a given
source is I0. On passing through 37.5 mm of lead
it is reduced to I0/8. The thickness of lead which
will reduce it to I0/2 is
(1) (37.5) 1/3 mm (2) (37.5) 1/4 mm
(3) 37.5/3 mm (4) (37.5/4) mm
Q.47 A proton moving with a velocity 3 × 10 5 ms –1
enters a magnetic field of 0.3 tesla at an angle of
30º with the field. The radius of curvature of its
path will be (e/m for proton ≈ 10 8 C/kg)
(1) 0.02 cm (2) 0.5 cm
(3) 2 cm (4) 1.25 cm
Q.48 If mass-energy equivalence is taken into account,
when water is cooled to form ice, the mass of
water should -
(1) increase
(2) remain unchanged
(3) decrease
(4) first increase then decrease
Q.44 le; t = 0 ij {k;kad λ1 ds N1 ukfHkd rFkk {k;kad λ2 ds
N2 ukfHkd fefJr fd;s tkrs gSA feJ.k dh {k; nj gS&
( 1 2)
t
(1) N1N
2e
λ + λ −
−
⎛ N 1 ⎞ −(
λ1+
λ2
) t
(2) −
⎜ e
N ⎟
⎝ 2 ⎠
−λ
t
−λ
t
1 1 1 2
( 1 2 ) t
1 1N
2 2e
λ + λ −
λ λ
1
2
(3) − ( N λ e + N λ e )
(4) − N
Q.45 Mh czksXyh rjaxnS/;Z λ ds bysDVªkWu ,d X-fdj.k ufydk
esa y{; ij fxjrs gSA mRlftZr X-fdj.kksa dh vUrd
(cut-off) rjaxnS/;Z gS&
2 λ
(1) λ 0 =
(2)
h
CAREER POINT, CP Tower, Road No.1, IPIA, Kota (Raj.), Ph: 0744-3040000 Page # 10
mc 2
2
2
3
2h
0
mc
= λ
2m
c λ
(3) λ0 =
(4) λ0 = λ
2
h
Q.46 ,d fn;s x;s L=kksr ls izkIr xkek fofdj.k dh rhozrk I0
gSA 37.5 mm dh lhls dh ifêdk ls xqtjus ij bldh
rhozrk ?kVdj I0/8 gks tkrh gSA lhls dh ifêdk dh
eksVkbZ tks bldh rhozrk ?kVkdj I0/2 dj ns] gS&
(1) (37.5) 1/3 mm (2) (37.5) 1/4 mm
(3) 37.5/3 mm (4) (37.5/4) mm
Q.47 ,d izksVkWu 3 × 10 5 ms –1 ds osx ls xfr djrk gqvk
0.3 Vslyk ds ,d pqEcdh; {ks=k esa {ks=k ls 30º ds dks.k
ij izos'k djrk gSA blds iFk dh oØrk f=kT;k gksxh&
(izksVkWu ds fy, e/m ≈ 10 8 C/kg)
(1) 0.02 cm (2) 0.5 cm
(3) 2 cm (4) 1.25 cm
Q.48 ;fn nzO;eku&ÅtkZ rqY;kad dks ekuk tk;s rks tc ty
dks B.Mk dj cQZ esa cnyk tkrk gS] rks ty dk
nzO;eku&
(1) c