Physics-
General
Easy
Question
Lux is equal to
- 1 lumen/m2
- 1 lumen/cm2
- 1 candela/m2
- 1 candela/cm2
The correct answer is: 1 candela/m2
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Related Questions to study
physics-
A 60 watt bulb is hung over the center of a table 
at a height of 3 m. The ratio of the intensities of illumination at a point on the centre of the edge and on the corner of the table is
A 60 watt bulb is hung over the center of a table at a height of 3 m. The ratio of the intensities of illumination at a point on the centre of the edge and on the corner of the table is
physics-General
maths-
If f(x) is a polynomial of degree five with leading coefficient one such that f(1)=12,f(2)=22,f(3)=32,f(4)=42,f(5)=52 then
If f(x) is a polynomial of degree five with leading coefficient one such that f(1)=12,f(2)=22,f(3)=32,f(4)=42,f(5)=52 then
maths-General
maths-
If f(x) = ax2+ bx + c such that f(p) + f(q) = 0 where a
0 ; p , q
R then number of real roots of equation f(x) = 0in interval [p, q] is
f(p)=–f(q) 
eitherf(p)f(q)<0 or f(p) =0=f(q)
exactlyonerootin(p,q) orrootsarepandq
eitherf(p)f(q)<0 or f(p) =0=f(q) exactlyonerootin(p,q) orrootsarepandqIf f(x) = ax2+ bx + c such that f(p) + f(q) = 0 where a0 ; p , qR then number of real roots of equation f(x) = 0in interval [p, q] is
maths-General
f(p)=–f(q) eitherf(p)f(q)<0 or f(p) =0=f(q)
exactlyonerootin(p,q) orrootsarepandq
eitherf(p)f(q)<0 or f(p) =0=f(q) exactlyonerootin(p,q) orrootsarepandqmaths-
If f(x) is a differentiable function satisfying f(x+ y)= f(x)f(y) 
x, y R and f'(0)=2 then f(x)=
If f(x) is a differentiable function satisfying f(x+ y)= f(x)f(y) x, y R and f'(0)=2 then f(x)=
maths-General
physics-
Maximum kinetic energy (Ek ) of a photoelectron varies with the frequency ( v ) of the incident radiation as
Maximum kinetic energy (Ek ) of a photoelectron varies with the frequency ( v ) of the incident radiation as
physics-General
maths-
The degree of the differential equation satisfying 
is
The degree of the differential equation satisfying is
maths-General
Maths-
If 
then the solution of the equation is :
If then the solution of the equation is :
Maths-General
physics-
A simple magnifying lens is used in such a way that an image is formed at 25 cm away from the eye. In order to have 10 times magnification, the focal length of the lens should be
or 
A simple magnifying lens is used in such a way that an image is formed at 25 cm away from the eye. In order to have 10 times magnification, the focal length of the lens should be
physics-General
or Maths-
The differential equation of all circles which pass through the origin and whose centres lie on y-axis is
The differential equation of all circles which pass through the origin and whose centres lie on y-axis is
Maths-General
maths-
Let p, q{1,2,3,4}.Then number of equation of the form px2+qx+1=0,having real roots ,is
q2–4p
0
q=2 p=1
q=3 p=1,2
q=4 p=1,2,3,4
Hence 7 values of (p, q)7equationsarepossible.
0q=2
p=1q=3
p=1,2q=4
p=1,2,3,4Hence 7 values of (p, q)7equationsarepossible.
Let p, q{1,2,3,4}.Then number of equation of the form px2+qx+1=0,having real roots ,is
maths-General
q2–4p0
q=2 p=1
q=3 p=1,2
q=4 p=1,2,3,4
Hence 7 values of (p, q)7equationsarepossible.
0q=2
p=1q=3
p=1,2q=4
p=1,2,3,4Hence 7 values of (p, q)7equationsarepossible.
maths-
Number of values of 'p' for which the equation
possess more than two roots ,is:
For (p2– 3p+2)x2–(p2–5p+4)x+p–p2=0tobe anidentity
p2–3p+2 =0 p = 1, 2...(i)
p2 – 5p + 4 = 0 p = 1, 4...(ii)
p – p2 = 0 p = 0, 1...(iii)
For (i), (ii) & (iii) to hold simultaneously p = 1.
p2–3p+2 =0
p = 1, 2...(i)p2 – 5p + 4 = 0
p = 1, 4...(ii)p – p2 = 0
p = 0, 1...(iii)For (i), (ii) & (iii) to hold simultaneously p = 1.
Number of values of 'p' for which the equation possess more than two roots ,is:
maths-General
For (p2– 3p+2)x2–(p2–5p+4)x+p–p2=0tobe anidentity
p2–3p+2 =0 p = 1, 2...(i)
p2 – 5p + 4 = 0 p = 1, 4...(ii)
p – p2 = 0 p = 0, 1...(iii)
For (i), (ii) & (iii) to hold simultaneously p = 1.
p2–3p+2 =0
p = 1, 2...(i)p2 – 5p + 4 = 0
p = 1, 4...(ii)p – p2 = 0
p = 0, 1...(iii)For (i), (ii) & (iii) to hold simultaneously p = 1.
maths-
Statement-1- The number 
is not divisible by 11.Because
Statement-2- If p is a prime, the exponent of p in n! is 
+ 
+ 
+……Where [x] denotes the greatest integer 
x.
Statement-1- The number is not divisible by 11.Because
Statement-2- If p is a prime, the exponent of p in n! is + + +……Where [x] denotes the greatest integer x.
maths-General
physics-
According to Newton’s law of cooling, the rate of cooling is proportional to 
, where 
is the temperature differences between the body and the surroundings and
is equal to
According to Newton’s law of cooling the rate of loss of heat of a body is directly proportional to the difference in temperature of the body, 
(i)
Given,
(ii)
Comparing Eqs. (i) and (ii), we get
=1
(i)Given,
(ii)Comparing Eqs. (i) and (ii), we get
=1According to Newton’s law of cooling, the rate of cooling is proportional to , where is the temperature differences between the body and the surroundings and is equal to
physics-General
According to Newton’s law of cooling the rate of loss of heat of a body is directly proportional to the difference in temperature of the body,
(i)
Given, (ii)
Comparing Eqs. (i) and (ii), we get
=1
(i)Given,
(ii)Comparing Eqs. (i) and (ii), we get
=1Maths-
satisfies the relation 
then value of A and B respectively are:
satisfies the relation then value of A and B respectively are:
Maths-General
physics-
Radius of a conductor increases uniformly from left end to right end as shown in fig 
Material of the conductor is isotropic and its curved surface is thermally insulated from surrounding. Its ends are maintained at temperatures 
and 
: If, in steady state, heat flow rate is equal to 
, then which of the following graphs is correct
Since the curved surface of the conductor is thermally insulated, therefore, in steady state, the rate of flow of heat at every section will be the same. Hence the curve between and 
will be straight line parallel to -axis
and will be straight line parallel to -axisRadius of a conductor increases uniformly from left end to right end as shown in fig Material of the conductor is isotropic and its curved surface is thermally insulated from surrounding. Its ends are maintained at temperatures and : If, in steady state, heat flow rate is equal to , then which of the following graphs is correct
physics-General
Since the curved surface of the conductor is thermally insulated, therefore, in steady state, the rate of flow of heat at every section will be the same. Hence the curve between and will be straight line parallel to -axis
and will be straight line parallel to -axis