The resultant capacitance in the fig above is
- A. 15.0µF
- B. 9.8µF
- C. 1.3µF
- D. 0.8µF
The fig above shows two similar bulbs X and Y connected to suitable power supply with F as an appropriate fuse rating, if the filament of X breaks then the
- A. Brightness Of Y will reduce
- B. Brightness Of Y will remain constant
- C. Brightness Of Y will increase
- D. fuse F will blow
A body of mass 40kg is being dragged along the floor by a rope inclined at 60 degrees to the horizontal. The frictional force between the box and the floor is 100N and the tension on the rope is 300N. How much work is done by dragging the box for a distance of 4m
- A. 680J
- B. 400J
- C. 200J
- D. 100J
The acceleration of the system show above is
- A. 2ms-2
- B. 4ms-2
- C. 6ms-2
- D. 8ms-2
The value of T in the figure above is
- A. 10.0N
- B. 11.8N
- C. 20.0N
- D. 40.0N
In the above fig, PQ and R are vectors, which of the following options, gives a correct relationship between the vectors?
- A. P = Q + R
- B. P = Q - R
- C. P = R - Q
- D. P + Q + R = O
An alternating source is connected in series to a capacitor of capacity reactance \( 10^3 \sqrt{3} \) and a resistor of resistance 103 Ohms. The Impedance of the circuit is…
- A. \( 2000 \sqrt{3} \) Ohms
- B. 2000 Ohms
- C. \( 1000 \sqrt{3} \) Ohms
- D. 1000 Ohms
The half-life of a radio-active element is 9 days, what fraction of atoms has decayed in 36 days?
- A. \( \frac{1}{16} \)
- B. \( \frac{1}{4} \)
- C. \( \frac{1}{2} \)
- D. \( \frac{15}{16} \)
A light of energy 5eV falls on a metal and the electrons with a maximum kinetic energy of 2eV are ejected. The work function of the metal is
- A. 0.4eV
- B. 2.5eV
- C. 3.0eV
- D. 7.0eV
The primary winding of a transformer has 400 turns and its secondary has 100 turns. If a source of e.m.f. of 12V is applied to the primary, the secondary e.m.f. will be
- A. 3V
- B. 6V
- C. 24V
- D. 48V
Which of the following is required to convert a milliammeter to an ammeter?
- A. A high resistance in parallel
- B. A high resistance in series
- C. A low resistance in parallel
- D. A low resistance in series
If the maximum voltage across a 100ohms resistor is 20V, then the maximum power it can dissipate is
- A. 5.00W
- B. 4.00W
- C. 2.00W
- D. 25W
An electric current of 2 amperes flows in a heating coil of resistance 50 ohms for 3 minutes 20 seconds. Determine the heat produced
- A. 0.5kJ
- B. 8.0kJ
- C. 20.0kJ
- D. 40.0kJ
The purpose of a dielectric material in a parallel plate capacitor is to
- A. increase its capacitance
- B. decrease its capacitance
- C. insulate the plate from each other
- D. increase the magnetic field between the plates
A 12V battery has an internal resistance of 0.5W.If a cable of 1.0W resistance is connected across the two terminals of the battery, the current drawn from the battery is
- A. 16.0A
- B. 8.0A
- C. 0.8A
- D. 0.4A
If a resistance is halved in value and the potential difference across it is tripled, then the ratio of the new current to the old one is
- A. 1 : 6
- B. 1 : 3
- C. 2 : 1
- D. 6 : 1
At different locations on the earth’s surface, the earth’s magnetic field is
- A. the same in magnitude and direction
- B. the same in magnitude but different in direction
- C. different in both magnitude and direction
- D. different in magnitude but different in direction
Two parallel plates at a distance of 8.0 x 10-3m apart are maintained at a p.d of 600 volts with the negative plate earthed. What is the electric field strength?
- A. 4.8 Vm-1
- B. 75.0Vm-1
- C. 4800.0Vm-1
- D. 75000.0Vm-1
Which of the following pairs of colours gives the widest separation in the spectrum of white light?
- A. Red and Violet
- B. Green and Yellow
- C. Red and Indigo
- D. Yellow and Violet
A real object is placed at a distance ucm in front of a curved mirror of focal length fcm. If the image is upright and magnified, then the mirror is
- A. convex and u =2f
- B. concave and u = 2f
- C. convex and u = f
- D. concave and u = f
What is the approximate critical angle for total internal reflection for diamond if the refractive index of diamond is 2.42?
- A. 21o
- B. 22o
- C. 23o
- D. 24o