# [Solved] JEXPO 2018 Physics Question Paper

### [Solved] JEXPO 2018 Physics Question Paper

JEXPO 2018 Chemistry Question Paper with Solution

Q.1) What is the angle between incident and reflected rays when a ray of light is incident normally on a plane mirror? 90° 45°  180°

Correct Answer: 180°

Explanation

When ray of light incident normally on a plane mirror, then incident angle = 0°.
∴ Reflection angle also be 0° [according to the 2nd law of reflection of light].
Again, we know that in that case direction of incident ray and reflected ray are opposite to each other.
Hence, the required angle must be 180°.

Q.2) Which mirror has a wider field of view? cylindrical mirror concave mirror plane mirror convex mirror

Correct Answer: convex mirror

Explanation

Convex mirror because a mirror is diverging in nature. Light rays incident at its extreme corners gets diverged following laws of reflection. Hence if we draw the diagram we can clearly understand that the reflected rays follow a wider path. While in case of a plane mirror the divergence is not so large.

Q.3) An object of size 2.0 cm is placed perpendicular to the principal axis of a concave mirror. The distance of the object from the mirror equals the radius of curvature. The size of the image will be 1.5 cm 0.5 cm 1.0 cm 2.0 cm

Correct Answer: 2.0 cm

Explanation

Size of the image must be same as the object size if an object is placed perpendicular to the principal axis of a concave mirror at a distance equal to 2f or r (radius of curvature).

Q.4) On a rainy day, small oily films on water show brilliant colours. This is due to scattering interference dispersion polarisation

Correct Answer: interference

Explanation

No explanation

Q.5) Variation of resistance of semiconductor with temperature is represented by which graph?        Correct Answer:  Explanation

For semiconductor, resistance decreases with increases the temperature.

Q.6) How much work is done in moving 4C across two points having potential difference 10V? 40J 2.5J 0.4J 10J

Correct Answer: 40J

Explanation

Work-done in moving a electrical charge, W = Potential difference (V) × amount of charge (Q) ⇒ 10 × 4 Joules = 40 J

Q.7) Rectifier is used to convert AC to DC low voltage to high voltage DC to AC None of those

Correct Answer: AC to DC

Explanation

No explanation.

JEXPO 2018 Chemistry Question Paper with Solution

Q.8) If a 24V and a 10V battery series opposing, total voltage is 34V 10V 24V 14V

Correct Answer: 14V

Explanation

According to the question, both the batteries are connected in opposite direction.
Thus, total voltage = (24 − 10) V ⇒ 14 V

Q.9) What is the equivalent resistance between A and B? 3 Ω 2 Ω 4 Ω 1 Ω

Correct Answer: 2 Ω

Explanation

4Ω and 2Ω are connected in series [see figure].
∴ Equivalent resistance of 4Ω and 2Ω resistances = (4 + 2)Ω ⇒ 6Ω.
Again 6Ω and 3Ω resistances are connected in parallel combination.
Thus, the required equivalent resistance between A and B =

6×36+3=2 Ω

Q.10) A car runs on a circular track at a constant speed. The circular track has a radius of 100 m. If the car takes 62.8 seconds on each lap, it’s average speed is 20 ms−1 5 ms−1 10 ms−1 Zero

Correct Answer: 10 ms−1

Explanation

By the definition of average speed, we have
Average speed =

total distance  total time⇒

circumference of circular track  total time⇒

2×3.14×100  62.8ms−1 = 10 ms−1

Q.11) Two persons start running towards each other from two points that are 120 m apart. First person runs with a speed of 5 m/s and the other with a speed of 7 m/s. Both the persons meet after 10s 24s 48s 1 min

Correct Answer: 