1
MCQ (Single Correct Answer)

JEE Main 2017 (Online) 8th April Morning Slot

In an experiment a sphere of aluminium of mass 0.20 kg is heated upto 150oC. Immediately, it is put into water of volume 150 cc at 27oC kept in a calorimeter of water equivalent to 0.025 kg. Final temperature of the system is 40oC. The specific heat of aluminium is : (take 4.2 Joule = 1 calorie)
A
378 J/kg $$-$$oC
B
315 J/kg $$-$$oC
C
476 J/kg $$-$$oC
D
434 J/kg $$-$$oC

Explanation

Let specific heat of aluminium = S,

As we know from principle of calorimetry,

Qgiven = Qused

$$\therefore\,\,\,$$ 0.2 $$ \times $$ S $$ \times $$ (150 $$-$$ 40) =
150 $$ \times $$ 1 $$ \times $$ (40 $$-$$ 27) + 25 $$ \times $$ (40$$-$$27)

$$ \Rightarrow $$$$\,\,\,$$ 0.2 $$ \times $$ S $$ \times $$ 110 = 150 $$ \times $$ 13 + 25 $$ \times $$ 13

$$ \Rightarrow $$$$\,\,\,$$ S = 434 J/kg - oC
2
MCQ (Single Correct Answer)

JEE Main 2017 (Online) 9th April Morning Slot

In an experiment a convex lens of focal length 15 cm is placed coaxially on an optical bench in front of a convex mirror at a distance of 5 cm from it. It is found that an object and its image coincide, if the object is placed at a distance of 20 cm from the lens. The focal length of the convex mirror is :
A
27.5 cm
B
20.0 cm
C
25.0 cm
D
30.5 cm
3
MCQ (Single Correct Answer)

JEE Main 2017 (Online) 9th April Morning Slot

In an experiment to determine the period of a simple pendulum of length 1 m, it is attached to different spherical bobs of radii r1 and r2 . The two spherical bobs have uniform mass distribution. If the relative difference in the periods, is found to be 5×10−4 s, the difference in radii, $$\left| {} \right.$$r1 $$-$$ r2 $$\left| {} \right.$$ is best given by :
A
1 cm
B
0.05 cm
C
0.5 cm
D
0.01 cm
4
MCQ (Single Correct Answer)

JEE Main 2018 (Online) 16th April Morning Slot

In a circuit for finding the resistance of a galvanometer by half deflection method, a 6 V battery and a high resistance of 11 k$$\Omega $$ are used. The figure of merit of the galvanometer is 60 $$\mu A/$$division. In the absence of shunt resistance, the galvanometer produces a deflection of $$\theta $$ = 9 divisions when current flows in the circuit. The value of the shunt resistance that can cause the deflection of $$\theta /2,$$ is closest to :
A
500 $$\Omega $$
B
220 $$\Omega $$
C
55 $$\Omega $$
D
110 $$\Omega $$

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE ME GATE PI GATE EE GATE CE GATE IN

Medical

NEET