**Q1.**According to Newton’s law of cooling, the rate of cooling of a body is proportional to (Δθ)^{n} , where Δθ is the difference of the temperature of the body and the surroundings, and n is equal to

(a) two

(b) three

(c) four

(d) one

**Q2. **Alternating current can not be measured by D.C. ammeter because

(a) Average value of current for complete cycle is zero

(b) A.C. Changes direction

(c) A.C. can not pass through D.C. Ammeter

(d) D.C. Ammeter will get damaged.

**Q3. **An alpha nucleus of energy 1/2 mv^{2} bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to

(a) v^{2}

(b) 1/m

(c) 1/v^{2}

(d) 1/Ze

**Q4. **An astronomical telescope has a large aperture to

(a) reduce spherical aberration

(b) have high resolution

(c) increase span of observation

(d) have low dispersion.

**Q5. **An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

(a) 200 J – 500 J ** **(b) 2 × 10

^{5}J – 3 × 10

^{5}J

**(c) 20, 000 J – 50,000 J**

**(d) 2,000 J – 5, 000 J**

**Q6.**An automobile travelling with a speed of 60 km/h, can brake to stop within a distance of 20m. If the car is going twice as fast i.e., 120 km/h, the stopping distance will be

(a) 60 m

**(b) 40 m**

**(c) 20 m**

**(d) 80 m**

**Q7.**An electric bulb is rated 220 volt – 100 watt. The power consumed by it when operated on 110 volt will be

(a) 75 watt

(b) 40 watt

(c) 25 watt

(d) 50 watt

**Q8. **An electric dipole is placed at an angle of 30° to a nonuniform electric field. The dipole will experience

(a) a translational force only in the direction of the field

(b) a translational force only in a direction normal to the direction of the field

(c) a torque as well as a translational force

(d) a torque only

**Q9. **An electromagnetic wave of frequency r = 3.0 MHz passes from vacuum into a dielectric medium with permittivity ∊ = 0.4. Then

(a) wave length is halved and frequency remains unchanged

(b) wave length is doubled and frequency becomes half

(c) wave length is doubled and the frequency remains unchanged

(d) wave length and frequency both remain unchanged.

**Q10. **An energy source will supply a constant current into the load if its internal resistance is

(a) very large as compared to the load resistance

(b) equal to the resistance of the load

(c) non-zero but less than the resistance of the load

(d) zero

1.d2.a3.b4.b5.d6.d7.c8.c9.a10.d