# If a machine is lubricated with oil:

2.  Its efficiency increases

3.  Its mechanical advantage and efficiency increase

4.  Its efficiency increases but its mechanical advantage decreases

4

Its mechanical advantage and efficiency increase

Explanation :
No Explanation available for this question

# When 4 identical wires of copper, iron, gold and silver are stretched by a tension of 4kgm, velocity of the transverse waves in them is

1.  Same

2.  Different

3.  Infinite

4.  Zero

4

Different

Explanation :
No Explanation available for this question

# An electric bulb illuminates a plane surface. The intensity of illumination on the surface at a point 2m away from the bulb is 5 x 10-6 Photon. The line joining the bulb to the point makes an angle of 600 with the normal to the surface. The intensity of the bulb will be:

1.  40√3candela

2.  40candela

3.   20candela

4.  40 x 10-4candela

4

Explanation :
No Explanation available for this question

# The main source of energy in the Sun is

1.  The fusion of uranium present in the Sun

2.  The burning of hydrogen in oxygen

3.  The energy liberated in fusion of protons during the synthesis of heavier nuclei

4.  Gravitational contraction

5.

5

Gravitational contraction

Explanation :
No Explanation available for this question

# Which one of the following rays has greatest value of wavelength

1.  Infrared ray

2.  Ultra violet

3.  Yellow ray

4.  Red ray

5.

5

Ultra violet

Explanation :
No Explanation available for this question

# Two coils A and B made of the same material are connected in parallel across the mains. If length and diameter of the coil A is double that of the coil B, which one will produce more heat

1.  Coil A

2.  Coil B

3.  Both the coils will produce the same amount of heat

4.  Cannot say

5.

5

Both the coils will produce the same amount of heat

Explanation :
No Explanation available for this question

# Ampere seconds stands for the unit of

1.  Power

2.  Energy

3.  e.m.f

4.  Charge

5.

5

Energy

Explanation :
No Explanation available for this question

# What will be the ratio of gravitational force (Fg) and electrostatic force (Fe) between two electrons situated at a distance of 10cm

1.  1043

2.  1036

3.  10-43

4.  10-36

5.

5

10-36

Explanation :
No Explanation available for this question

# To use triode as an amplifier, it is operated in the

1.  Curved portion of the characteristics curve

2.   Straight portion of the characteristics curve

3.  Bottom portion of the curve

4.  Top portion of the curve

5.

5

Straight portion of the characteristics curve

Explanation :
No Explanation available for this question

# A directly heated diode gives:

1.  Delayed response

2.  Immediate response

3.  No response

4.  A and Bare true

5.

5